Detector for determining a position of at least one object

ABSTRACT

A detector ( 118 ) for determining a position of at least one object ( 112 ) is disclosed, the detector ( 118 ) comprising:
         at least one longitudinal optical sensor ( 120 ), wherein the longitudinal optical sensor ( 120 ) has at least one sensor region ( 124 ), wherein the longitudinal optical sensor ( 120 ) is at least partially transparent, wherein the longitudinal optical sensor ( 120 ) is designed to generate at least one longitudinal sensor signal in a manner dependent on an illumination of the sensor region ( 124 ) by at least one light beam ( 126 ) traveling from the object ( 112 ) to the detector ( 118 ), wherein the longitudinal sensor signal, given the same total power of the illumination, is dependent on a beam cross-section of the light beam ( 126 ) in the sensor region ( 124 );   at least one illumination source ( 114 ) adapted to illuminate the object ( 112 ) with illumination light ( 115 ) through the longitudinal optical sensor ( 120 ); and   at least one evaluation device ( 136 ), wherein the evaluation device ( 136 ) is designed to generate at least one item of information on a longitudinal position of the object ( 112 ) by evaluating the longitudinal sensor signal.

FIELD OF THE INVENTION

The invention relates to a detector for determining a position of atleast one object, a human-machine interface, a tracking system, acamera, a method for determining a position of at least one object andvarious uses of the detector. Such devices and such methods can beemployed for example in various areas of daily life, traffic technology,production technology, security technology, medical technology,entertainment technology or in the sciences. Additionally oralternatively, the application may be applied in the field of mapping ofspaces, such as for generating maps of one or more rooms, one or morebuildings or one or more streets. Further, the detector may form acamera or may be part of a camera for imaging at least one object.However, other applications are also possible in principle.

PRIOR ART

A large number of detectors configured to determine a position of anobject are known from the prior art. Such detectors for determining theposition of the object are known on the basis of optical sensors andphotovoltaic devices.

While photovoltaic devices are generally used to convert electromagneticradiation, for example, ultraviolet, visible or infrared light, intoelectrical signals or electrical energy, optical detectors are generallyused for picking up image information and/or for detecting at least oneoptical parameter, for example, a brightness. In general, opticalsensors can be based on the use of inorganic and/or organic sensormaterials. Examples of such sensors are disclosed in US 2007/0176165 A1,U.S. Pat. No. 6,995,445 B2, DE 2501124 A1, DE 3225372 A1 or else innumerous other prior art documents. To an increasing extent, inparticular for cost reasons and for reasons of large-area processing,sensors comprising at least one organic sensor material are being used,as described for example in US 2007/0176165 A1. In particular, so-calleddye solar cells are increasingly of importance here, which are describedgenerally, for example in WO 2009/013282 A1.

The detectors based on such optical sensors for determining a positionof at least one object can be embodied in diverse ways, depending on therespective purpose of use. Examples of such detectors are imagingdevices, for example, cameras and/or microscopes. High-resolutionconfocal microscopes are known, for example, which can be used inparticular in the field of medical technology and biology in order toexamine biological samples with high optical resolution. Furtherexamples of detectors for optically detecting objects are triangulationsystems, by means of which a distance measurement can be carried out.

Further examples of detectors for optically detecting at least oneobject are distance measuring devices based, for example, on propagationtime methods of corresponding optical signals, for example laser pulses.In general, these detectors may comprise an illumination source, e.g. alamp or a laser, and a light-detecting device. The illumination sourcemay emit light, in particular one or more light beams, which are focusedby a lens and/or a lens system. The emitted light may be reflected bythe object. The reflected light may be detected by the light-detectingdevice. In general, these detectors may use techniques as time-of-flightanalysis, structure light analysis or a plurality of detectors forexample for performing triangulation methods, for determining a positionof an object. Other methods are based in turn on complex pulsesequences, such as, for example, distance measurements by means of laserpulses.

Various position detectors are known in the art. Thus, in JP 8-159714 A,a distance measurement device is disclosed. Therein, by using a detectorand a shadow-forming element, a distance between an object and thedetector is determined based on the fact that shadow formation ofobjects depends on the distance. In US 2008/0259310 A1, an opticalposition detector is disclosed. The position of a transmission system isdetermined by using a variety of known distances and measured angles. InUS 2005/0184301 A1, a distance measurement device is disclosed. Themeasurement device makes use of a plurality of light-emitting diodeshaving different wavelengths. In CN 101650173 A, a position detector isdisclosed which is based on the use of geometric principles. Further, inJP 10-221064 A, a complex optical setup is disclosed which is similar tooptical setups used in holography.

In U.S. Pat. No. 4,767,211, a device and a method for opticalmeasurement and imaging are disclosed. Therein, a ratio of reflectedlight traveling along an optical axis and reflected light travelingoff-axis is determined by using different photo-detectors and a divider.By using this principal, depressions in a sample may be detected.

In U.S. Pat. No. 4,647,193, a range of a target object is determined byusing a detector having multiple components. The detector is placed awayfrom a focal plane of a lens. The size of a light spot of light from theobject varies with the range of the object and, thus, is dependent onthe range of the object. By using different photo-detectors, the size ofthe light spot and, thus, the range of the object may be determined bycomparing signals generated by the photo-detectors.

In U.S. Pat. No. 6,995,445 and US 2007/0176165 A1, a position sensitiveorganic detector is disclosed. Therein, a resistive bottom electrode, isused which is electrically contacted by using at least two electricalcontacts. By forming a current ratio of the currents from the electriccontacts, a position of a light spot on the organic detector may bedetected.

In WO 2010/088032 A2 and US 2011/0055846 A1, a capture device configuredto obtain depth images of one or more targets is proposed. The capturedevice may include a depth camera, a video camera, stereo cameras,and/or other suitable capture devices. The capture device may include animage camera component, which may include an IR light component, athree-dimensional (3-D) camera, and/or an RGB camera. In WO 2010/088032A2, the capture device may be configured to capture videos with depthinformation by any suitable technique (e.g., time-of-flight, structuredlight, stereo image, etc.). In addition to the techniques used in WO2010/088032 A2, in US 2011/0055846 A1, the phase of the outgoing lightwave may be compared to the phase of the incoming light wave todetermine a phase shift, which is used to determine a physical distanceof the object.

In general, two problems may occur during the usage of such detectorsknown from prior art:

Firstly, a parallax problem may occur, because of the opacity of theused components, it typically is not possible to arrange theillumination source, the position detector, the lens and/or lens system,and an image camera on a same optical axis. Usually, one or more of theillumination source, the position detector and the image camera may bedisplaced from the optical axis. This displacement may yield on the onehand to a limitation of the design and on the other hand to aninaccuracy of the distance measurement, such that, when combininginformation of the position detector and the image camera, the imagetaken by the image camera may be displaced from the image of theposition detector. For example, this parallaxes problem is shown in FIG.4.21 of “KINECT DEPTH SENSOR EVALUATION FOR COMPUTER VISIONAPPLICATIONS”, p. 27-30, Technical Report ECE-TR-6, Aarhus University.It is shown that the depth- and the RGB-images are not aligned. Thisparallax problem may be corrected but this correction demands additionalcomputing power.

Secondly, shadows, i.e. regions which are seen by the detector but whichare not illuminated by the illumination source, may occur in the imageof the detector. In FIG. 4.23 of “KINECT DEPTH SENSOR EVALUATION FORCOMPUTER VISION APPLICATIONS”, p. 27-30, Technical Report ECE-TR-6,Aarhus University, it is shown that illuminated objects may causeshadows due to the distance between the illuminator and the IR camera.

Transparent or at least partially transparent position detectors aregenerally known from prior art. WO 2012/110924 A1, the content of whichis herewith included by reference, discloses a detector for opticallydetecting at least one object. The detector comprises at least oneoptical sensor. The optical sensor has at least one sensor region. Theoptical sensor is designed to generate at least one sensor signal in amanner dependent on an illumination of the sensor region. The sensorsignal, given the same total power of the illumination, is dependent ona geometry of the illumination, in particular on a beam cross section ofthe illumination on the sensor area. The detector furthermore has atleast one evaluation device. The evaluation device is designed togenerate at least one item of geometrical information from the sensorsignal, in particular at least one item of geometrical information aboutthe illumination and/or the object.

U.S. provisional applications 61/739,173, filed on Dec. 19, 2012,61/749,964, filed on Jan. 8, 2013, and 61/867,169, filed on Aug. 19,2013, and international patent application PCT/IB2013/061095, publishedunder WO2014/097181 A1, filed on Dec. 18, 2013, the full content of allof which is herewith included by reference, disclose a method and adetector for determining a position of at least one object, by using atleast one transversal optical sensor and at least one optical sensor.Specifically, the use of sensor stacks is disclosed, in order todetermine a longitudinal position of the object with a high degree ofaccuracy and without ambiguity.

European patent application number EP 13171898.3, filed on Jun. 13,2013, the full content of which is herewith included by reference,discloses an optical detector comprising an optical sensor having asubstrate and at least one photosensitive layer setup disposed thereon.The photosensitive layer setup has at least one first electrode at leastone second electrode and at least one photovoltaic material sandwichedin between the first electrode and the second electrode. Thephotovoltaic material comprises at least one organic material. The firstelectrode comprises a plurality of first electrode stripes, and thesecond electrode comprises a plurality of second electrode stripes,wherein the first electrode stripes and the second electrode stripesintersect such that a matrix of pixels is formed at intersections of thefirst electrode stripes and the second electrode stripes. The opticaldetector further comprises at least one readout device, the readoutdevice comprising a plurality of electrical measurement devices beingconnected to the second electrode stripes and a switching device forsubsequently connecting the first electrode stripes to the electricalmeasurement devices.

European patent application number EP 13171900.7, also filed on Jun. 13,2013, the full content of which is herewith included by reference,discloses a detector device for determining an orientation of at leastone object, comprising at least two beacon devices being adapted to beat least one of attached to the object, held by the object andintegrated into the object, the beacon devices each being adapted todirect light beams towards a detector, and the beacon devices havingpredetermined coordinates in a coordinate system of the object. Thedetector device further comprises at least one detector adapted todetect the light beams traveling from the beacon devices towards thedetector and at least one evaluation device, the evaluation device beingadapted to determine longitudinal coordinates of each of the beacondevices in a coordinate system of the detector. The evaluation device isfurther adapted to determine an orientation of the object in thecoordinate system of the detector by using the longitudinal coordinatesof the beacon devices.

European patent application number EP 13171901.5, filed on Jun. 13,2013, the full content of which is herewith included by reference,discloses a detector for determining a position of at least one object.The detector comprises at least one optical sensor being adapted todetect a light beam traveling from the object towards the detector, theoptical sensor having at least one matrix of pixels. The detectorfurther comprises at least one evaluation device, the evaluation devicebeing adapted to determine a number N of pixels of the optical sensorwhich are illuminated by the light beam. The evaluation device isfurther adapted to determine at least one longitudinal coordinate of theobject by using the number N of pixels which are illuminated by thelight beam.

However, there is still a need to overcome the problems due toparallaxes and shadowing and to allow compact detectors configured todetermine a position of an object.

Problem Addressed by the Invention

Therefore, a problem addressed by the present invention is that ofspecifying devices and a method for determining a position of at leastone object which at least substantially avoid the disadvantages of knowndevices and methods of this type. In particular, the proposed devicesand methods are intended to make it possible to determine the positionof the at least one object without the occurrence of parallaxes andshadowing problems.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates the occurrence of shadows in a determination of aposition of at least one object.

FIG. 2 shows an exemplary embodiment of a detector according to thepresent invention;

FIG. 3 shows a further exemplary embodiment of the detector according tothe present invention.

FIG. 4 shows an exemplary embodiment of the detector used in ahuman-machine interface, an entertainment device and a tracking system.

FIG. 5 shows a modification of the embodiment of FIG. 2, having amovable reflective element.

FIG. 6 shows a modification of the embodiment of FIG. 3, wherein thebeam-splitting device is embodied as a movable reflective element.

FIG. 7 shows a modification of the detector of FIG. 2, having anadditional illumination source and a movable reflective element.

FIG. 8 shows an exemplary embodiment of a detector containing one ormore time-of-flight detectors.

DISCLOSURE OF THE INVENTION

This problem is solved by a detector, a human-machine-interface, atracking system, a method with the features of the independent patentclaims. Preferred embodiments which might be realized in an isolatedfashion or in arbitrary combination are listed in the dependent claims.

As used in the following, the terms “have”, “comprise” or “include” orany arbitrary grammatical variations thereof are used in a non-exclusiveway. Thus, these terms may both refer to a situation in which, besidesthe feature introduced by these terms, no further features are presentin the entity described in this context and to a situation in which oneor more further features are present. As an example, the expressions “Ahas B”, “A comprises B” and “A includes B” may refer to a situation inwhich, besides B, no other element is present in A (i.e. a situation inwhich a solely and exclusively consists of B) and to a situation inwhich, besides B, one or more further elements are present in entity A,such as element C, elements C and D or even further elements.

Further, as used in the following, the terms “preferably”, “morepreferably”, “more preferably”, “particularly”, “more particularly”,“specifically”, “more specifically” or similar terms are used inconjunction with optional features, without restricting alternativepossibilities. Thus, features introduced by these terms are optionalfeatures and are not intended to restrict the scope of the claims in anyway. The invention may, as the skilled person will recognize, beperformed by using alternative features. Similarly, features introducedby “in an embodiment of the invention” or similar expressions areintended to be optional features, without any restriction regardingalternative embodiments of the invention, without any restrictionsregarding the scope of the invention and without any restrictionregarding the possibility of combining the features introduced in suchway with other optional or non-optional features of the invention.

In a first aspect of the invention a detector for determining a positionof at least one object is proposed. The detector comprises:

-   -   at least one longitudinal optical sensor, wherein the        longitudinal optical sensor has at least one sensor region,        wherein the longitudinal optical sensor is at least partially        transparent, wherein the longitudinal optical sensor is designed        to generate at least one longitudinal sensor signal in a manner        dependent on an illumination of the sensor region by at least        one light beam traveling from the object to the detector,        wherein the longitudinal sensor signal, given the same total        power of the illumination, is dependent on a beam cross-section        of the light beam in the sensor region;    -   at least one illumination source adapted to illuminate the        object with illumination light through the longitudinal optical        sensor;    -   at least one evaluation device, wherein the evaluation device is        designed to generate at least one item of information on a        longitudinal position of the object by evaluating the        longitudinal sensor signal.

As used herein, a detector generally refers to a device which is capableof generating at least one detector signal and/or at least one image, inresponse to an illumination by one or more illumination sources and/orin response to optical properties of a surrounding of the detector.Thus, the detector may be an arbitrary device adapted for performing atleast one of an optical measurement and imaging process.

Specifically, the detector is adapted for determining a position of atleast one object. As used herein, the term position generally refers toat least one item of information regarding a location and/or orientationof the object and/or at least one part of the object in space. The atleast one item of information may imply at least one distance between atleast one point of the object and the at least one detector. As will beoutlined in further detail below, the distance may be a longitudinalcoordinate or may contribute to determine a longitudinal coordinate ofthe point of the object. Additionally or alternatively, one or moreother items of information regarding the location and/or orientation ofthe object and/or at least one part of the object may be determined. Asan example, at least one transversal coordinate of the object and/or atleast one part of the object may be determined. Thus, the position ofthe object may imply at least one longitudinal coordinate of the objectand/or at least one part of the object. Additionally or alternatively,the position of the object may imply at least one transversal coordinateof the object and/or at least one part of the object. Additionally oralternatively, the position of the object may imply at least oneorientation information of the object, indicating an orientation of theobject in space. The position may relate to the entire object or elseonly a part, for example a point, an area or a region of the object.Said part can be arranged on a surface of the object or else at leastpartly within the object.

For this purpose, as an example, one or more coordinate systems may beused, and the position of the object may be determined by using one,two, three or more coordinates. As an example, one or more Cartesiancoordinate systems and/or other types of coordinate systems may be used.In one example, the coordinate system may be a coordinate system of thedetector in which the detector has a predetermined position and/ororientation. As will be outlined in further detail below, the detectormay have an optical axis, which may constitute a main direction of viewof the detector. The optical axis may form an axis of the coordinatesystem, such as a z-axis. Further, one or more additional axes may beprovided, preferably perpendicular to the z-axis.

Thus, as an example, the detector may constitute a coordinate system inwhich the optical axis forms the z-axis and in which, additionally, anx-axis and a y-axis may be provided which are perpendicular to thez-axis and which are perpendicular to each other. As an example, thedetector and/or a part of the detector may rest at a specific point inthis coordinate system, such as at the origin of this coordinate system.In this coordinate system, a direction parallel or antiparallel to thez-axis may be regarded as a longitudinal direction, and a coordinatealong the z-axis may be considered a longitudinal coordinate. Anarbitrary direction perpendicular to the longitudinal direction may beconsidered a transversal direction, and an x- and/or y-coordinate may beconsidered a transversal coordinate.

Alternatively, other types of coordinate systems may be used. Thus, asan example, a polar coordinate system may be used in which the opticalaxis forms a z-axis and in which a distance from the z-axis and a polarangle may be used as additional coordinates. Again, a direction parallelor antiparallel to the z-axis may be considered a longitudinaldirection, and a coordinate along the z-axis may be considered alongitudinal coordinate. Any direction perpendicular to the z-axis maybe considered a transversal direction, and the polar coordinate and/orthe polar angle may be considered a transversal coordinate.

The object generally may be an arbitrary object. In one embodiment, theobject may be a rigid object. Other embodiments are feasible, such asembodiments in which the object is a non-rigid object or an object whichmay change its shape. The object can be detected completely or partly bymeans of the detector. The object generally may be an arbitrary object,chosen from a living object and a non-living object. Thus, as anexample, the at least one object may comprise one or more articlesand/or one or more parts of an article. Additionally or alternatively,the object may be or may comprise one or more living beings and/or oneor more parts thereof, such as one or more body parts of a human being,e.g. a user, and/or an animal.

As will be outlined in further detail below, the present invention mayspecifically be used for tracking positions and/or motions of a person,such as for the purpose of controlling machines, gaming or simulation ofsports. In this or other embodiments, specifically, the object may beselected from the group consisting of: an article of sports equipment,preferably an article selected from the group consisting of a racket, aclub, a bat; an article of clothing; a hat; a shoe.

The detector comprises at least one longitudinal optical sensor. As usedherein, a longitudinal optical sensor generally is a device which isdesigned to generate at least one longitudinal sensor signal in a mannerdependent on an illumination of the sensor region by at least one thelight beam traveling from the object to the detector. The longitudinalsensor signal, given the same total power of the illumination, isdependent on a beam cross-section of the light beam in the sensorregion.

The at least one longitudinal optical sensor may comprise a sensor stackof longitudinal optical sensors. The sensor stack may be composed oflongitudinal optical sensors being arranged such that the sensor regionsof the longitudinal optical sensors are oriented essentiallyperpendicular to an optical axis of the detector.

In case a plurality of longitudinal optical sensors is comprised, e. g.a stack of longitudinal optical sensors, the longitudinal opticalsensors may be identical or may be different such that at least twodifferent types of optical sensors may be comprised. As outlined infurther detail below, the at least one longitudinal optical sensor maycomprise at least one of an inorganic optical sensor and an organicoptical sensor. As used herein, an organic optical sensor generallyrefers to an optical sensor having at least one organic materialincluded therein, preferably at least one organic photosensitivematerial. Further, hybrid optical sensors may be used including bothinorganic and organic materials.

For potential embodiments of the longitudinal optical sensor, referencemay be made to the optical sensor as disclosed in WO 2012/110924 A1.Preferably, however, as will be outlined in further detail below, thedetector according to the present invention may comprise a plurality ofoptical sensors, such as a plurality of optical sensors as disclosed inWO 2012/110924 A1, preferably as a sensor stack. Thus, as an example,the detector according to the present invention may comprise a stack ofoptical sensors as disclosed in WO 2012/110924 A1.

In case the detector comprises at least one stack of optical sensors,the stack comprising at least two longitudinal optical sensors, thestack optionally may partially or fully be immersed in an oil and/or aliquid to avoid/decrease reflections at interfaces. Thus, at least oneof the optical sensors of the stack may fully or partially be immersedin the oil and/or the liquid.

As will further be outlined below, preferably, the longitudinal opticalsensor may comprise one or more photo detectors, preferably one or moreorganic photodetectors and, most preferably, one or more dye-sensitizedorganic solar cells (DSCs, also referred to as dye solar cells), such asone or more solid dye-sensitized organic solar cells (s-DSCs). Thus,preferably, the detector may comprise one or more DSCs (such as one ormore sDSCs) acting as the at least one longitudinal optical sensor andone or more DSCs (such as one or more sDSCs) acting as the at least onelongitudinal optical sensor, preferably a stack of a plurality of DSCs(preferably a stack of a plurality of sDSCs) acting as the at least onelongitudinal optical sensor.

The longitudinal optical sensor has at least one sensor region.Preferably, the sensor region of the longitudinal optical sensor may beformed by one continuous sensor region, such as one continuous sensorarea or sensor surface per device. Thus, preferably, the sensor regionof the longitudinal optical sensor or, in case a plurality oflongitudinal optical sensors is provided (such as a stack oflongitudinal optical sensors), each sensor region of the longitudinaloptical sensor, may be formed by exactly one continuous sensor region.

The at least one longitudinal optical sensor may have a sensor regionproviding a sensitive area, also referred to as a sensor area, of atleast 1 mm², preferably of at least 5 mm², such as a sensor area of 5mm² to 1000 cm², preferably a sensor area of 7 mm² to 100 cm², morepreferably a sensor area of 1 cm². The sensor area preferably has arectangular geometry, such as a square geometry. However, othergeometries and/or sensor areas are feasible.

Preferably, the longitudinal optical sensor may be a thin film device,having a layer setup of layers including electrode and photovoltaicmaterial, the layer setup having a thickness of preferably no more than1 mm, more preferably of at most 100 μm, at most 5 μm or even less.Thus, the sensor region of the longitudinal optical sensor preferablymay be or may comprise a sensor area, which may be formed by a surfaceof the respective device facing towards the object.

The longitudinal optical sensor is at least partially transparent. Thus,generally, the longitudinal optical sensor may comprise at least one atleast partially transparent optical sensor such that the light beam atleast partially may pass through the longitudinal optical sensor. Asused herein, the term “at least partially transparent” may both refer tothe option that the entire longitudinal optical sensor is transparent ora part (such as a sensitive region) of the longitudinal optical sensoris transparent and/or to the option that the longitudinal optical sensoror at least a transparent part of the longitudinal optical sensor maytransmit the light beam in an attenuated or non-attenuated fashion.Thus, as an example, the transparent longitudinal optical sensor mayhave a transparency of at least 10%, preferably at least 20%, at least40%, at least 50% or at least 70%. In order to provide a sensory effect,generally, the longitudinal optical sensor typically has to provide somesort of interaction between the light beam and the longitudinal opticalsensor which typically results in a loss of transparency. Thetransparency of the longitudinal optical sensor may be dependent on awavelength of the light beam, resulting in a spectral profile of asensitivity, an absorption or a transparency of the longitudinal opticalsensor. In case a plurality of longitudinal optical sensors is provided,such as a stack of longitudinal optical sensors, preferably alllongitudinal optical sensors of the plurality and/or the stack aretransparent.

As outlined above, in case a plurality of longitudinal optical sensorsis provided, the spectral properties of the optical sensors notnecessarily have to be identical. Thus, one of the longitudinal opticalsensors may provide a strong absorption (such as absorption peak) in thered spectral region, another one of the longitudinal optical sensors mayprovide a strong absorption in the green spectral region, and anotherone may provide a strong absorption in the blue spectral region. Otherembodiments are feasible. As used herein, the term light generallyrefers to electromagnetic radiation in one or more of the visiblespectral range, the ultraviolet spectral range and the infrared spectralrange. Therein, the term visible spectral range generally refers to aspectral range of 380 nm to 780 nm. The term infrared spectral rangegenerally refers to electromagnetic radiation in the range of 780 nm to1 mm, preferably in the range of 780 nm to 3.0 micrometers. The termultraviolet spectral range generally refers to electromagnetic radiationin the range of 1 nm to 380 nm, preferably in the range of 100 nm to 380nm. Further, the spectral range of 600 nm to 780 nm may be defined asthe red spectral range, the range of 490 nm to 600 nm as the greenspectral range, and the range of 380 nm to 490 nm as the blue spectralrange.

The longitudinal sensor signal preferably may be selected from the groupconsisting of a current (such as a photocurrent) and a voltage (such asa photovoltage). Further, the longitudinal sensor signal may bepreprocessed, in order to derive refined sensor signals from raw sensorsignals, such as by averaging and/or filtering. The longitudinal sensorsignal may, additionally or alternatively, depend on other properties ofthe light beam such as a width of the light beam. The longitudinalsensor signal preferably may be an electrical signal, such as anelectrical current and/or an electric voltage. The longitudinal sensorsignal may be a continuous or discontinuous signal. Further, thelongitudinal sensor signal may be an analogue signal or a digitalsignal. Further, the longitudinal optical sensor, by itself and/or inconjunction with other components of the longitudinal optical detector,may be adapted to process or preprocess the longitudinal sensor signal,such as by filtering and/or averaging, in order to provide a processedlongitudinal sensor signal. Thus, as an example, a bandpass filter maybe used in order to transmit only longitudinal sensor signals of aspecific frequency range. Other types of preprocessing are feasible. Inthe following, when referring to the longitudinal sensor signal, nodifference will be made between the case in which the raw longitudinalsensor signal is used and the case in which a preprocessed longitudinalsensor signal is used for further evaluation.

As used herein, a “light beam” generally is an amount of light travelinginto more or less the same direction. Thus, preferably, a light beam mayrefer to a Gaussian light beam, as known to the skilled person. However,other light beams, such as non-Gaussian light beams, are possible. Asoutlined in further detail below, the light beam may be emitted and/orreflected by an object. Further, the light beam may be reflected and/oremitted.

As outlined above, the at least one longitudinal sensor signal, giventhe same total power of the illumination by the light beam, is dependenton a beam cross-section of the light beam in the sensor region of the atleast one longitudinal optical sensor. As used herein, the term “beamcross-section” generally refers to a lateral extension of the light beamor a light spot generated by the light beam at a specific location. Incase a circular light spot is generated, a radius, a diameter or aGaussian beam waist or twice the Gaussian beam waist may function as ameasure of the beam cross-section. In case non-circular light-spots aregenerated, the cross-section may be determined in any other feasibleway, such as by determining the cross-section of a circle having thesame area as the non-circular light spot, which is also referred to asthe equivalent beam cross-section.

Thus, given the same total power of the illumination of the sensorregion by the light beam, a light beam having a first beam diameter orbeam cross-section may generate a first longitudinal sensor signal,whereas a light beam having a second beam diameter or beam-cross sectionbeing different from the first beam diameter or beam cross-sectiongenerates a second longitudinal sensor signal being different from thefirst longitudinal sensor signal. Thus, by comparing the longitudinalsensor signals, an information or at least one item of information onthe beam cross-section, specifically on the beam diameter, may begenerated. For details of this effect, reference may be made to WO2012/110924 A1.

In the following, this effect generally will be referred to as theFiP-effect, since, given the same total power p of illumination, thesensor signal i is dependent on a flux F of photons, i.e. the number ofphotons per unit area.

This effect, which is further disclosed in U.S. provisional applications61/739,173 and 61/749,964, may be used for determining a longitudinalposition of an object from which the light beam travels towards thedetector. Thus, since the sensor signal of the longitudinal opticalsensor depends on a width, such as a diameter or radius, of the lightbeam on the sensor region, which again depends on a distance between thedetector and the object, the longitudinal sensor signal may be used fordetermining a longitudinal coordinate of the object. The sensor regionpreferably may be a non-pixelated sensor region. Thus, as an example,the evaluation device may be adapted to use a predetermined relationshipbetween a longitudinal coordinate of the object and a sensor signal inorder to determine the longitudinal coordinate. The predeterminedrelationship may be derived by using empiric calibration measurementsand/or by using known beam propagation properties, such as Gaussian beampropagation properties. For further details, reference may be made to WO2012/110924 A1 and/or U.S. provisional applications 61/739,173 and61/749,964.

Preferably, in case a plurality of longitudinal optical sensors isprovided, such as a stack of longitudinal optical sensors, at least twoof the longitudinal optical sensors may be adapted to provide the FiPeffect. Thus, by evaluating signals from longitudinal optical sensorswhich subsequently are illuminated by the light beam, such as subsequentlongitudinal optical sensors of a sensor stack, ambiguities in a beamprofile may be resolved. Thus, Gaussian light beams may provide the samebeam width at a distance z before and after a focal point. By measuringthe beam width along at least two positions, this ambiguity may beresolved, by determining whether the light beam still is narrowing orwidening. Thus, providing two or more longitudinal optical sensorshaving the FiP-effect, a higher accuracy may be provided. The evaluationdevice may be adapted to determine the widths of the light beam in thesensor regions of the at least two optical sensors, and the evaluationdevice may further be adapted to generate at least one item ofinformation on a longitudinal position of an object from which the lightbeam propagates towards the optical detector, by evaluating the widths.

For details of this FiP effect, reference may be made to one or more ofWO 2012/110924 A1 or U.S. provisional applications 61/739,173, filed onDec. 19, 2012, 61/749,964, filed on Jan. 8, 2013, and 61/867,169, filedon Aug. 19, 2013, and international patent applicationPCT/IB2013/061095, filed on Dec. 18, 2013. Specifically in case one ormore beam properties of the light beam propagating from the object tothe detector are known, the at least one item of information on thelongitudinal position of the object may thus be derived from a knownrelationship between the at least one longitudinal sensor signal and alongitudinal position of the object. The known relationship may bestored in the evaluation device as an algorithm and/or as one or morecalibration curves. As an example, specifically for Gaussian beams, arelationship between a beam diameter or beam waist and a position of theobject may easily be derived by using the Gaussian relationship betweenthe beam waist and a longitudinal coordinate.

The detector comprises at least one longitudinal optical sensor. Thus,the detector may comprise one or more of the longitudinal opticalsensors. In case a plurality of two or more longitudinal optical sensorsare provided, the longitudinal optical sensors may be arranged invarious ways, such as by providing a sensor stack comprising two or moreof the longitudinal optical sensors in a stacked fashion.

Besides the at least one longitudinal optical sensor, the detector may,optionally, comprise one or more additional optical sensors which arenot longitudinal optical sensors according to the definition givenherein. Thus, as an example, the detector may comprise a stack ofoptical sensors, wherein at least one of the optical sensors is alongitudinal optical sensor and wherein at least another one of theoptical sensors is a different type of optical sensor, such as atransversal optical sensor and/or an imaging device, such as an organicimaging sensor and/or an inorganic imaging sensor like a CCD and/or CMOSchip.

Thus, the detector may further comprise at least one transversal opticalsensor, the transversal optical sensor being adapted to determine atransversal position of at least one light beam traveling from theobject to the detector, the transversal position being a position in atleast one dimension perpendicular an optical axis of the detector, thetransversal optical sensor being adapted to generate at least onetransversal sensor signal. The evaluation device may be designed togenerate at least one item of information on a transversal position ofthe object by evaluating the transversal sensor signal.

As used herein, the term transversal optical sensor generally refers toa device which is adapted to determine a transversal position of atleast one light beam traveling from the object to the detector. Withregard to the term transversal position, reference may be made to thedefinition given above. Thus, preferably, the transversal position maybe or may comprise at least one coordinate in at least one dimensionperpendicular to an optical axis of the detector. As an example, thetransversal position may be a position of a light spot generated by thelight beam in a plane perpendicular to the optical axis, such as on alight-sensitive sensor surface of the transversal optical sensor. As anexample, the position in the plane may be given in Cartesian coordinatesand/or polar coordinates. Other embodiments are feasible.

For potential embodiments of the transversal optical sensor, referencemay be made to the position sensitive organic detector as disclosed inU.S. Pat. No. 6,995,445 and US 2007/0176165 A1. However, otherembodiments are feasible and will be outlined in further detail below.

The at least one transversal sensor signal generally may be an arbitrarysignal indicative of the transversal position. As an example, thetransversal sensor signal may be or may comprise a digital and/or ananalog signal. As an example, the transversal sensor signal may be ormay comprise a voltage signal and/or a current signal. Additionally oralternatively, the transversal sensor signal may be or may comprisedigital data. The transversal sensor signal may comprise a single signalvalue and/or a series of signal values. The transversal sensor signalmay further comprise an arbitrary signal which is derived by combiningtwo or more individual signals, such as by averaging two or more signalsand/or by forming a quotient of two or more signals, as will be outlinedin further detail below.

Thus, as an example, the detector according to the present invention maycomprise a stack of optical sensors as disclosed in WO 2012/110924 A1,in combination with one or more transversal optical sensors. As anexample, one or more transversal optical sensors may be disposed on aside of the stack of longitudinal optical sensors facing towards theobject. Alternatively or additionally, one or more transversal opticalsensors may be disposed on a side of the stack of longitudinal opticalsensors facing away from the object. Again, additionally oralternatively, one or more transversal article sensors may be interposedin between the longitudinal optical sensors of the stack.

As will further be outlined below, preferably, both the at least onetransversal optical sensor longitudinal optical sensor and the at leastone longitudinal optical sensor may comprise one or more photodetectors, preferably one or more organic photodetectors and, mostpreferably, one or more dye-sensitized organic solar cells (DSCs, alsoreferred to as dye solar cells), such as one or more soliddye-sensitized organic solar cells (s-DSCs). Thus, preferably, thedetector may comprise one or more DSCs (such as one or more sDSCs)acting as the at least one transversal optical sensor and one or moreDSCs (such as one or more sDSCs) acting as the at least one longitudinaloptical sensor, preferably a stack of a plurality of DSCs (preferably astack of a plurality of sDSCs) acting as the at least one longitudinaloptical sensor.

In case at least one transversal optical sensor is provided, preferably,the transversal optical sensor is a photo detector having at least onefirst electrode, at least one second electrode and at least onephotovoltaic material, wherein the photovoltaic material is embedded inbetween the first electrode and the second electrode. As used herein, aphotovoltaic material generally is a material or combination ofmaterials adapted to generate electric charges in response to anillumination of the photovoltaic material with light.

Preferably, the second electrode of the transversal optical sensor maybe a split electrode having at least two partial electrodes, wherein thetransversal optical sensor has a sensor area, wherein the at least onetransversal sensor signal indicates a position of the light beam in thesensor area. Thus, as outlined above, the transversal optical sensor maybe or may comprise one or more photo detectors, preferably one or moreorganic photo detectors, more preferably one or more DSCs or sDSCs. Thesensor area may be a surface of the photo detector facing towards theobject. The sensor area preferably may be oriented perpendicular to theoptical axis. Thus, the transversal sensor signal may indicate aposition of a light spot generated by the light beam in a plane of thesensor area of the transversal optical sensor.

Generally, as used herein, the term partial electrode refers to anelectrode out of a plurality of electrodes, adapted for measuring atleast one current and/or voltage signal, preferably independent fromother partial electrodes. Thus, in case a plurality of partialelectrodes is provided, the second electrode is adapted to provide aplurality of electric potentials and/or electric currents and/orvoltages via the at least two partial electrodes, which may be measuredand/or used independently.

When using at least one transversal optical sensor having at least onesplit electrode having two or more partial electrodes as a secondelectrode, currents through the partial electrodes may be dependent on aposition of the light beam in the sensor area. This may generally be dueto the fact that Ohmic losses or resistive losses may occur on the wayfrom a location of generation of electrical charges due to the impinginglight to the partial electrodes. Thus, besides the partial electrodes,the second electrode may comprise one or more additional electrodematerials connected to the partial electrodes, wherein the one or moreadditional electrode materials provide an electrical resistance. Thus,due to the Ohmic losses on the way from the location of generation ofthe electric charges to the partial electrodes through with the one ormore additional electrode materials, the currents through the partialelectrodes depend on the location of the generation of the electriccharges and, thus, to the position of the light beam in the sensor area.For details of this principle of determining the position of the lightbeam in the sensor area, reference may be made to the preferredembodiments below and/or to the physical principles and device optionsas disclosed e.g. in U.S. Pat. No. 6,995,445 and/or US 2007/0176165 A1.

The transversal optical sensor may further be adapted to generate thetransversal sensor signal in accordance with the electrical currentsthrough the partial electrodes. Thus, a ratio of electric currentsthrough two horizontal partial electrodes may be formed, therebygenerating an x-coordinate, and/or a ratio of electric currents throughto vertical partial electrodes may be formed, thereby generating ay-coordinate. The detector, preferably the transversal optical sensorand/or the evaluation device, may be adapted to derive the informationon the transversal position of the object from at least one ratio of thecurrents through the partial electrodes. Other ways of generatingposition coordinates by comparing currents through the partialelectrodes are feasible.

The partial electrodes generally may be defined in various ways, inorder to determine a position of the light beam in the sensor area.Thus, two or more horizontal partial electrodes may be provided in orderto determine a horizontal coordinate or x-coordinate, and two or morevertical partial electrodes may be provided in order to determine avertical coordinate or y-coordinate. Thus, the partial electrodes may beprovided at a rim of the sensor area, wherein an interior space of thesensor area remains free and may be covered by one or more additionalelectrode materials. As will be outlined in further detail below, theadditional electrode material preferably may be a transparent additionalelectrode material, such as a transparent metal and/or a transparentconductive oxide and/or, most preferably, a transparent conductivepolymer.

Further preferred embodiments may refer to the photovoltaic material.Thus, the photovoltaic material of the transversal optical sensor maycomprise at least one organic photovoltaic material. Thus, generally,the transversal optical sensor may be an organic photo detector.Preferably, the organic photo detector may be a dye-sensitized solarcell. The dye-sensitized solar cell preferably may be a soliddye-sensitized solar cell, comprising a layer setup embedded in betweenthe first electrode and the second electrode, the layer setup comprisingat least one n-semiconducting metal oxide, at least one dye, and atleast one solid p-semiconducting organic material. Further details andoptional embodiments of the dye-sensitized solar cell (DSC) will bedisclosed below.

The at least one first electrode of the transversal optical sensorpreferably is transparent. As used in the present invention, the termtransparent generally refers to the fact that the intensity of lightafter transmission through the transparent object equals to or exceeds10%, preferably 40% and, more preferably, 60% of the intensity of lightbefore transmission through the transparent object. More preferably, theat least one first electrode of the transversal optical sensor may fullyor partially be made of at least one transparent conductive oxide (TCO).As an example, indium-doped tin oxide (ITO) and/or fluorine-doped tinoxide (FTO) may be named. Further examples will be given below.

Further, the at least one second electrode of the transversal opticalsensor preferably may fully or partially be transparent. Thus,specifically, the at least one second electrode may comprise two or morepartial electrodes and at least one additional electrode materialcontacting the two or more partial electrodes. The two or more partialelectrodes may be intransparent. As an example, the two or more partialelectrodes may fully or partially be made of a metal. Thus, the two ormore partial electrodes preferably are located at a rim of the sensorarea. The two or more partial electrodes, however, may electrically beconnected by the at least one additional electrode material which,preferably, is transparent. Thus, the second electrode may comprise anintransparent rim having the two or more partial electrodes and atransparent inner area having the at least one transparent additionalelectrode material. More preferably, the at least one second electrodeof the transversal optical sensor, such as the above-mentioned at leastone additional electrode material, may fully or partially be made of atleast one conductive polymer, preferably a transparent conductivepolymer. As an example, conductive polymers having an electricalconductivity of at least 0.01 S/cm may be used, preferably of at least0.1 S/cm or, more preferably, of at least 1 S/cm or even at least 10S/cm or at least 100 S/cm. As an example, the at least one conductivepolymer may be selected from the group consisting of: apoly-3,4-ethylenedioxythiophene (PEDOT), preferably PEDOT beingelectrically doped with at least one counter ion, more preferably PEDOTdoped with sodium polystyrene sulfonate (PEDOT:PSS); a polyaniline(PANI); a polythiophene.

As outlined above, the conductive polymer may provide an electricalconnection between the at least two partial electrodes. The conductivepolymer may provide an Ohmic resistivity, allowing for determining theposition of charge generation. Preferably, the conductive polymerprovides an electric resistivity of 0.1-20 kΩ between the partialelectrodes, preferably an electric resistivity of 0.5-5.0 kΩ and, morepreferably, an electric resistivity of 1.0-3.0 kΩ.

Generally, as used herein, a conductive material may be a material whichhave a specific electrical resistance of less than 10⁴, less than 10³,less than 10², or of less than 10 Ωm. Preferably, the conductivematerial has a specific electrical resistance of less than 10⁻¹, lessthan 10⁻², less than 10⁻³, less than 10⁻⁵, or less than 10⁻⁶ Ωm. Mostpreferably, the specific electrical resistance of the conductivematerial is less than 5×10⁻⁷ Ωm or is less than 1×10⁻⁷ Ωm, particularlyin the range of the specific electrical resistance of aluminum.

As outlined above, preferably, at least one of the transversal opticalsensor and the longitudinal optical sensor is a transparent opticalsensor. Thus, the at least one transversal optical sensor may be atransparent transversal optical sensor and/or may comprise at least onetransparent transversal optical sensor. Additionally or alternatively,the at least one longitudinal optical sensor may be a transparentlongitudinal optical sensor and/or may comprise at least one transparentlongitudinal optical sensor. In case a plurality of longitudinal opticalsensors is provided, such as a stack of longitudinal optical sensors,preferably all longitudinal optical sensors of the plurality and/or thestack or all longitudinal optical sensors of the plurality and/or thestack but one longitudinal optical sensor are transparent. As anexample, in case a stack of longitudinal optical sensors is provided,wherein the longitudinal optical sensors are arranged along the opticalaxis of the detector, preferably all longitudinal optical sensors butthe last longitudinal optical sensor facing away from the object may betransparent longitudinal optical sensors. The last longitudinal opticalsensor, i.e. the longitudinal optical sensor on the side of the stackfacing away from the object, may be a transparent longitudinal opticalsensor or an intransparent longitudinal optical sensor. Exemplaryembodiments will be given below.

The light beam may pass through the transparent optical sensor beforeimpinging on the other one of the transversal optical sensor and thelongitudinal optical sensor. Thus, the light beam from the object maysubsequently reach the transversal optical sensor and the longitudinaloptical sensor or vice versa.

Preferably, specifically in case one or more of the longitudinal opticalsensors provides that the above-mentioned FiP-effect, the at least onelongitudinal optical sensor or, in case a plurality of longitudinaloptical sensors provided, one or more of the longitudinal opticalsensors, may be or may comprise a DSC, preferably a sDSC. As usedherein, a DSC generally refers to a setup having at least twoelectrodes, wherein at least one of the electrodes is at least partiallytransparent, wherein at least one n-semiconducting metal oxide, at leastone dye and at least one electrolyte or p-semiconducting material isembedded in between the electrodes. In an sDSC, the electrolyte orp-semiconducting material is a solid material. Generally, for potentialsetups of sDSCs which may also be used for one or more of the opticalsensors within the present invention, reference may be made to one ormore of WO 2012/110924 A1, U.S. provisional applications 61/739,173 and61/749,964, EP 13171898.3, EP 13171900.7 or EP 13171901.5. Otherembodiments are feasible. The above-mentioned FiP-effect, asdemonstrated in WO 2012/110924 A1, specifically may be present in sDSCs.

Thus, generally, the at least one longitudinal optical sensor maycomprise at least one longitudinal optical sensor having a layer setup.The longitudinal optical sensor may comprise at least one firstelectrode, at least one n-semiconducting metal oxide, at least one dye,at least one p-semiconducting organic material, preferably a solidp-semiconducting organic material, and at least one second electrode.Both of the first electrode and the second electrode may be transparent.

As outlined above, the at least one longitudinal optical sensor or, incase a plurality of longitudinal optical sensors is provided, at leastone of the longitudinal optical sensors may be an organic optical sensorcomprising a photosensitive layer setup having at least two electrodesand at least one photovoltaic material embedded in between theseelectrodes. In the following, examples of a preferred setup of thephotosensitive layer setup will be given, specifically with regard tomaterials which may be used within this photosensitive layer setup. Thephotosensitive layer setup preferably is a photosensitive layer setup ofa solar cell, more preferably an organic solar cell and/or adye-sensitized solar cell (DSC), more preferably a solid dye-sensitizedsolar cell (sDSC). Other embodiments, however, are feasible.

Preferably, the photosensitive layer setup comprises at least onephotovoltaic material, such as at least one photovoltaic layer setupcomprising at least two layers, sandwiched between the first electrodeand the second electrode. Preferably, the photosensitive layer setup andthe photovoltaic material comprise at least one layer of ann-semiconducting metal oxide, at least one dye and at least onep-semiconducting organic material. As an example, the photovoltaicmaterial may comprise a layer setup having at least one dense layer ofan n-semiconducting metal oxide such as titanium dioxide, at least onenano-porous layer of an n-semiconducting metal oxide contacting thedense layer of the n-semiconducting metal oxide, such as at least onenano-porous layer of titanium dioxide, at least one dye sensitizing thenano-porous layer of the n-semiconducting metal oxide, preferably anorganic dye, and at least one layer of at least one p-semiconductingorganic material, contacting the dye and/or the nano-porous layer of then-semiconducting metal oxide.

The dense layer of the n-semiconducting metal oxide, as will beexplained in further detail below, may form at least one barrier layerin between the first electrode and the at least one layer of thenano-porous n-semiconducting metal oxide. It shall be noted, however,that other embodiments are feasible, such as embodiments having othertypes of buffer layers.

The at least two electrodes comprise at least one first electrode and atleast one second electrode. The first electrode may be one of an anodeor a cathode, preferably an anode. The second electrode may be the otherone of an anode or a cathode, preferably a cathode. The first electrodepreferably contacts the at least one layer of the n-semiconducting metaloxide, and the second electrode preferably contacts the at least onelayer of the p-semiconducting organic material. The first electrode maybe a bottom electrode, contacting a substrate, and the second electrodemay be a top electrode facing away from the substrate. Alternatively,the second electrode may be a bottom electrode, contacting thesubstrate, and the first electrode may be the top electrode facing awayfrom the substrate. Preferably, both the first electrode and the secondelectrode are transparent.

In the following, some options regarding the first electrode, the secondelectrode and the photovoltaic material, preferably the layer setupcomprising two or more photovoltaic materials, will be disclosed. Itshall be noted, however, that other embodiments are feasible.

a) Substrate, First Electrode and n-Semiconductive Metal Oxide

Generally, for preferred embodiments of the first electrode and then-semiconductive metal oxide, reference may be made to WO 2012/110924A1, U.S. provisional application No. 61/739,173 or U.S. provisionalapplication No. 61/708,058, the full content of all of which is herewithincluded by reference. Other embodiments are feasible.

In the following, it shall be assumed that the first electrode is thebottom electrode directly or indirectly contacting the substrate. Itshall be noted, however, that other setups are feasible, with the firstelectrode being the top electrode.

The n-semiconductive metal oxide which may be used in the photosensitivelayer setup, such as in at least one dense film (also referred to as asolid film) of the n-semiconductive metal oxide and/or in at least onenano-porous film (also referred to as a nano-particulate film) of then-semiconductive metal oxide, may be a single metal oxide or a mixtureof different oxides. It is also possible to use mixed oxides. Then-semiconductive metal oxide may especially be porous and/or be used inthe form of a nanoparticulate oxide, nanoparticles in this context beingunderstood to mean particles which have an average particle size of lessthan 0.1 micrometer. A nanoparticulate oxide is typically applied to aconductive substrate (i.e. a carrier with a conductive layer as thefirst electrode) by a sintering process as a thin porous film with largesurface area.

Preferably, the longitudinal optical sensor uses at least onetransparent substrate. The substrate may be rigid or else flexible.Suitable substrates (also referred to hereinafter as carriers) are, aswell as metal foils, in particular plastic sheets or films andespecially glass sheets or glass films. Particularly suitable electrodematerials, especially for the first electrode according to theabove-described, preferred structure, are conductive materials, forexample transparent conductive oxides (TCOs), for example fluorine-and/or indium-doped tin oxide (FTO or ITO) and/or aluminum-doped zincoxide (AZO), carbon nanotubes or metal films. Alternatively oradditionally, it would, however, also be possible to use thin metalfilms which still have a sufficient transparency.

The substrate can be covered or coated with these conductive materials.Since generally, only a single substrate is required in the structureproposed, the formation of flexible cells is also possible. This enablesa multitude of end uses which would be achievable only with difficulty,if at all, with rigid substrates, for example use in bank cards,garments, etc.

The first electrode, especially the TCO layer, may additionally becovered or coated with a solid or dense metal oxide buffer layer (forexample of thickness 10 to 200 nm), in order to prevent direct contactof the p-type semiconductor with the TCO layer (see Peng et aZ, Coord.Chem. Rev. 248, 1479 (2004)). The use of solid p-semiconductingelectrolytes, in the case of which contact of the electrolyte with thefirst electrode is greatly reduced compared to liquid or gel-formelectrolytes, however, makes this buffer layer unnecessary in manycases, such that it is possible in many cases to dispense with thislayer, which also has a current-limiting effect and can also worsen thecontact of the n-semiconducting metal oxide with the first electrode.This enhances the efficiency of the components. On the other hand, sucha buffer layer can in turn be utilized in a controlled manner in orderto match the current component of the dye solar cell to the currentcomponent of the organic solar cell. In addition, in the case of cellsin which the buffer layer has been dispensed with, especially in solidcells, problems frequently occur with unwanted recombinations of chargecarriers. In this respect, buffer layers are advantageous in many casesspecifically in solid cells.

As is well known, thin layers or films of metal oxides are generallyinexpensive solid semiconductor materials (n-type semiconductors), butthe absorption thereof, due to large bandgaps, is typically not withinthe visible region of the electromagnetic spectrum, but rather usuallyin the ultraviolet spectral region. For use in solar cells, the metaloxides therefore generally, as is the case in the dye solar cells, haveto be combined with a dye as a photosensitizer, which absorbs in thewavelength range of sunlight, i.e. at 300 to 2000 nm, and, in theelectronically excited state, injects electrons into the conduction bandof the semiconductor. With the aid of a solid p-type semiconductor usedadditionally in the cell as an electrolyte, which is in turn reduced atthe counter electrode, electrons can be recycled to the sensitizer, suchthat it is regenerated.

Of particular interest for use in organic solar cells are thesemiconductors zinc oxide, tin dioxide, titanium dioxide or mixtures ofthese metal oxides. The metal oxides can be used in the form ofnanocrystalline porous layers. These layers have a large surface areawhich is coated with the dye as a sensitizer, such that a highabsorption of sunlight is achieved. Metal oxide layers which arestructured, for example nanorods, give advantages such as higherelectron mobilities or improved pore filling by the dye.

The metal oxide semiconductors can be used alone or in the form ofmixtures. It is also possible to coat a metal oxide with one or moreother metal oxides. In addition, the metal oxides may also be applied asa coating to another semiconductor, for example GaP, ZnP or ZnS.

Particularly preferred semiconductors are zinc oxide and titaniumdioxide in the anatase polymorph, which is preferably used innanocrystalline form.

In addition, the sensitizers can advantageously be combined with alln-type semiconductors which typically find use in these solar cells.Preferred examples include metal oxides used in ceramics, such astitanium dioxide, zinc oxide, tin(IV) oxide, tungsten(VI) oxide,tantalum(V) oxide, niobium(V) oxide, cesium oxide, strontium titanate,zinc stannate, complex oxides of the perovskite type, for example bariumtitanate, and binary and ternary iron oxides, which may also be presentin nanocrystalline or amorphous form.

Due to the strong absorption that customary organic dyes and ruthenium,phthalocyanines and porphyrins have, even thin layers or films of then-semiconducting metal oxide are sufficient to absorb the requiredamount of dye. Thin metal oxide films in turn have the advantage thatthe probability of unwanted recombination processes falls and that theinternal resistance of the dye subcell is reduced. For then-semiconducting metal oxide, it is possible with preference to uselayer thicknesses of 100 nm up to 20 micrometers, more preferably in therange between 500 nm and approx. 3 micrometers.

b) Dye

In the context of the present invention, as usual in particular forDSCs, the terms “dye”, “sensitizer dye” and “sensitizer” are usedessentially synonymously without any restriction of possibleconfigurations. Numerous dyes which are usable in the context of thepresent invention are known from the prior art, and so, for possiblematerial examples, reference may also be made to the above descriptionof the prior art regarding dye solar cells. As a preferred example, oneor more of the dyes disclosed in WO 2012/110924 A1, U.S. provisionalapplication No. 61/739,173 or U.S. provisional application No.61/708,058 may be used, the full content of all of which is herewithincluded by reference. Additionally or alternatively, one or more of thedyes as disclosed in WO 2007/054470 A1 and/or WO 2012/085803 A1 may beused, the full content of which is included by reference, too.

Dye-sensitized solar cells based on titanium dioxide as a semiconductormaterial are described, for example, in U.S. Pat. No. 4,927,721, Nature353, p. 737-740 (1991) and U.S. Pat. No. 5,350,644, and also Nature 395,p. 583-585 (1998) and EP-A-1 176 646. The dyes described in thesedocuments can in principle also be used advantageously in the context ofthe present invention. These dye solar cells preferably comprisemonomolecular films of transition metal complexes, especially rutheniumcomplexes, which are bonded to the titanium dioxide layer via acidgroups as sensitizers.

Many sensitizers which have been proposed include metal-free organicdyes, which are likewise also usable in the context of the presentinvention. High efficiencies of more than 4%, especially in solid dyesolar cells, can be achieved, for example, with indoline dyes (see, forexample, Schmidt-Mende et at, Adv. Mater. 2005, 17, 813). U.S. Pat. No.6,359,211 describes the use, also implementable in the context of thepresent invention, of cyanine, oxazine, thiazine and acridine dyes whichhave carboxyl groups bonded via an alkylene radical for fixing to thetitanium dioxide semiconductor.

Particularly preferred sensitizer dyes in the dye solar cell proposedare the perylene derivatives, terrylene derivatives and quaterrylenederivatives described in DE 10 2005 053 995 A1 or WO 2007/054470 A1.Further, as outlined above, one or more of the dyes as disclosed in WO2012/085803 A1 may be used. Additionally or alternatively, one or moreof the dyes as disclosed in WO 2013/144177 A1 may be used. The fullcontent of WO 2013/144177 A1 and/or of EP 12162526.3 is herewithincluded by reference. Specifically, dye D-5 and/or dye R-3 may be used,which is also referred to as ID1338:

Preparation and properties of the Dye D-5 are disclosed in WO2013/144177 A1.

The use of these dyes, which is also possible in the context of thepresent invention, leads to photovoltaic elements with high efficienciesand simultaneously high stabilities. Further, additionally oralternatively, the following dye may be used, which also is disclosed inWO 2013/144177 A1, which is referred to as ID1456:

Further, one or both of the following rylene dyes may be used in thedevices according to the present invention, specifically in the at leastone optical sensor:

These dyes ID1187 and ID1167 fall within the scope of the rylene dyes asdisclosed in WO 2007/054470 A1, and may be synthesized using the generalsynthesis routes as disclosed therein, as the skilled person willrecognize.

The rylenes exhibit strong absorption in the wavelength range ofsunlight and can, depending on the length of the conjugated system,cover a range from about 400 nm (perylene derivatives I from DE 10 2005053 995 A1) up to about 900 nm (quaterrylene derivatives I from DE 102005 053 995 A1). Rylene derivatives I based on terrylene absorb,according to the composition thereof, in the solid state adsorbed ontotitanium dioxide, within a range from about 400 to 800 nm. In order toachieve very substantial utilization of the incident sunlight from thevisible into the near infrared region, it is advantageous to usemixtures of different rylene derivatives I. Occasionally, it may also beadvisable also to use different rylene homologs.

The rylene derivatives I can be fixed easily and in a permanent mannerto the n-semiconducting metal oxide film. The bonding is effected viathe anhydride function (x1) or the carboxyl groups —COOH or —COO— formedin situ, or via the acid groups A present in the imide or condensateradicals ((x2) or (x3)). The rylene derivatives I described in DE 102005 053 995 A1 have good suitability for use in dye-sensitized solarcells in the context of the present invention.

It is particularly preferred when the dyes, at one end of the molecule,have an anchor group which enables the fixing thereof to the n-typesemiconductor film. At the other end of the molecule, the dyespreferably comprise electron donors Y which facilitate the regenerationof the dye after the electron release to the n-type semiconductor, andalso prevent recombination with electrons already released to thesemiconductor.

For further details regarding the possible selection of a suitable dye,it is possible, for example, again to refer to DE 10 2005 053 995 A1. Byway of example, it is possible especially to use ruthenium complexes,porphyrins, other organic sensitizers, and preferably rylenes.

The dyes can be fixed onto or into the n-semiconducting metal oxidefilm, such as the nano-porous n-semiconducting metal oxide layer, in asimple manner. For example, the n-semiconducting metal oxide films canbe contacted in the freshly sintered (still warm) state over asufficient period (for example about 0.5 to 24 h) with a solution orsuspension of the dye in a suitable organic solvent. This can beaccomplished, for example, by immersing the metal oxide-coated substrateinto the solution of the dye.

If combinations of different dyes are to be used, they may, for example,be applied successively from one or more solutions or suspensions whichcomprise one or more of the dyes. It is also possible to use two dyeswhich are separated by a layer of, for example, CuSCN (on this subjectsee, for example, Tennakone, K. J., Phys. Chem. B. 2003, 107, 13758).The most convenient method can be determined comparatively easily in theindividual case.

In the selection of the dye and of the size of the oxide particles ofthe n-semiconducting metal oxide, the organic solar cell should beconfigured such that a maximum amount of light is absorbed. The oxidelayers should be structured such that the solid p-type semiconductor canefficiently fill the pores. For instance, smaller particles have greatersurface areas and are therefore capable of adsorbing a greater amount ofdyes. On the other hand, larger particles generally have larger poreswhich enable better penetration through the p-conductor.

c) p-Semiconducting Organic Material

As described above, the at least one photosensitive layer setup, such asthe photosensitive layer setup of the DSC or sDSC, can comprise inparticular at least one p-semiconducting organic material, preferably atleast one solid p-semiconducting material, which is also designatedhereinafter as p-type semiconductor or p-type conductor. Hereinafter, adescription is given of a series of preferred examples of such organicp-type semiconductors which can be used individually or else in anydesired combination, for example in a combination of a plurality oflayers with a respective p-type semiconductor, and/or in a combinationof a plurality of p-type semiconductors in one layer.

In order to prevent recombination of the electrons in then-semiconducting metal oxide with the solid p-conductor, it is possibleto use, between the n-semiconducting metal oxide and the p-typesemiconductor, at least one passivating layer which has a passivatingmaterial. This layer should be very thin and should as far as possiblecover only the as yet uncovered sites of the n-semiconducting metaloxide. The passivation material may, under some circumstances, also beapplied to the metal oxide before the dye. Preferred passivationmaterials are especially one or more of the following substances: Al₂O₃;silanes, for example CH₃SiCl₃; Al³⁺; 4-tert-butylpyridine (TBP); MgO;GBA (4-guanidinobutyric acid) and similar derivatives; alkyl acids;hexadecylmalonic acid (HDMA).

As described above, preferably one or more solid organic p-typesemiconductors are used—alone or else in combination with one or morefurther p-type semiconductors which are organic or inorganic in nature.In the context of the present invention, a p-type semiconductor isgenerally understood to mean a material, especially an organic material,which is capable of conducting holes, that is to say positive chargecarriers. More particularly, it may be an organic material with anextensive π-electron system which can be oxidized stably at least once,for example to form what is called a free-radical cation. For example,the p-type semiconductor may comprise at least one organic matrixmaterial which has the properties mentioned. Furthermore, the p-typesemiconductor can optionally comprise one or a plurality of dopantswhich intensify the p-semiconducting properties. A significant parameterinfluencing the selection of the p-type semiconductor is the holemobility, since this partly determines the hole diffusion length (cf.Kumara, G., Langmuir, 2002, 18, 10493-10495). A comparison of chargecarrier mobilities in different spiro compounds can be found, forexample, in T. Saragi, Adv. Funct. Mater. 2006, 16, 966-974.

Preferably, in the context of the present invention, organicsemiconductors are used (i.e. one or more of low molecular weight,oligomeric or polymeric semiconductors or mixtures of suchsemiconductors). Particular preference is given to p-type semiconductorswhich can be processed from a liquid phase. Examples here are p-typesemiconductors based on polymers such as polythiophene andpolyarylamines, or on amorphous, reversibly oxidizable, nonpolymericorganic compounds, such as the spirobifluorenes mentioned at the outset(cf., for example, US 2006/0049397 and the Spiro compounds disclosedtherein as p-type semiconductors, which are also usable in the contextof the present invention). Preference is also given to using lowmolecular weight organic semiconductors, such as the low molecularweight p-type semiconducting materials as disclosed in WO 2012/110924A1, preferably spiro-MeOTAD, and/or one or more of the p-typesemiconducting materials disclosed in Leijtens et al., ACS Nano, VOL. 6,NO. 2, 1455-1462 (2012). Additionally or alternatively, one or more ofthe p-type semiconducting materials as disclosed in WO 2010/094636 A1may be used, the full content of which is herewith included byreference. In addition, reference may also be made to the remarksregarding the p-semiconducting materials and dopants from the abovedescription of the prior art.

The p-type semiconductor is preferably producible or produced byapplying at least one p-conducting organic material to at least onecarrier element, wherein the application is effected for example bydeposition from a liquid phase comprising the at least one p-conductingorganic material. The deposition can in this case once again beeffected, in principle, by any desired deposition process, for exampleby spin-coating, doctor blading, knife-coating, printing or combinationsof the stated and/or other deposition methods.

The organic p-type semiconductor may especially comprise at least oneSpiro compound such as spiro-MeOTAD and/or at least one compound withthe structural formula:

in whichA¹, A², A³ are each independently optionally substituted aryl groups orheteroaryl groups,R¹, R², R³ are each independently selected from the group consisting ofthe substituents —R, —OR, —NR₂, -A⁴-OR and -A⁴-NR₂,where R is selected from the group consisting of alkyl, aryl andheteroaryl,andwhere A⁴ is an aryl group or heteroaryl group, andwhere n at each instance in formula I is independently a value of 0, 1,2 or 3,with the proviso that the sum of the individual n values is at least 2and at least two of the R¹, R² and R³ radicals are —OR and/or —NR₂.

Preferably, A² and A³ are the same; accordingly, the compound of theformula (I) preferably has the following structure (la)

More particularly, as explained above, the p-type semiconductor may thushave at least one low molecular weight organic p-type semiconductor. Alow molecular weight material is generally understood to mean a materialwhich is present in monomeric, nonpolymerized or nonoligomerized form.The term “low molecular weight” as used in the present contextpreferably means that the p-type semiconductor has molecular weights inthe range from 100 to 25 000 g/mol. Preferably, the low molecular weightsubstances have molecular weights of 500 to 2000 g/mol.

In general, in the context of the present invention, p-semiconductingproperties are understood to mean the property of materials, especiallyof organic molecules, to form holes and to transport these holes and/orto pass them on to adjacent molecules. More particularly, stableoxidation of these molecules should be possible. In addition, the lowmolecular weight organic p-type semiconductors mentioned may especiallyhave an extensive π-electron system. More particularly, the at least onelow molecular weight p-type semiconductor may be processable from asolution. The low molecular weight p-type semiconductor may especiallycomprise at least one triphenylamine. It is particularly preferred whenthe low molecular weight organic p-type semiconductor comprises at leastone Spiro compound. A Spiro compound is understood to mean polycyclicorganic compounds whose rings are joined only at one atom, which is alsoreferred to as the spiro atom. More particularly, the spiro atom may bespa-hybridized, such that the constituents of the spiro compoundconnected to one another via the spiro atom are, for example, arrangedin different planes with respect to one another.

More preferably, the Spiro compound has a structure of the followingformula:

where the aryl¹, aryl², aryl³, aryl⁴, aryl⁵, aryl⁶, aryl⁷, and aryl⁸radicals are each independently selected from substituted aryl radicalsand heteroaryl radicals, especially from substituted phenyl radicals,where the aryl radicals and heteroaryl radicals, preferably the phenylradicals, are each independently substituted, preferably in each case byone or more substituents selected from the group consisting of —O-alkyl,—OH, —F, —Cl, —Br and —I, where alkyl is preferably methyl, ethyl,propyl or isopropyl. More preferably, the phenyl radicals are eachindependently substituted, in each case by one or more substituentsselected from the group consisting of —O-Me, —OH, —F, —Cl, —Br and —I.

Further preferably, the spiro compound is a compound of the followingformula:

where R^(r), R^(s), R^(t), R^(u), R^(v), R^(w), R^(x) and R^(y) are eachindependently selected from the group consisting of —O-alkyl, —OH, —F,—Cl, —Br and —I, where alkyl is preferably methyl, ethyl, propyl orisopropyl. More preferably, R^(r), R^(s), R^(t), R^(u), R^(v), R^(w),R^(x) and R^(y) are each independently selected from the groupconsisting of —O-Me, —OH, —F, —Cl, —Br and —I.

More particularly, the p-type semiconductor may comprise spiro-MeOTAD orconsist of spiro-MeOTAD, i.e. a compound of the formula below,commercially available from Merck KGaA, Darmstadt, Germany:

Alternatively or additionally, it is also possible to use otherp-semiconducting compounds, especially low molecular weight and/oroligomeric and/or polymeric p-semiconducting compounds.

In an alternative embodiment, the low molecular weight organic p-typesemiconductor comprises one or more compounds of the above-mentionedgeneral formula I, for which reference may be made, for example, to PCTapplication number PCT/EP2010/051826. The p-type semiconductor maycomprise the at least one compound of the above-mentioned generalformula I additionally or alternatively to the spiro compound describedabove.

The term “alkyl” or “alkyl group” or “alkyl radical” as used in thecontext of the present invention is understood to mean substituted orunsubstituted C₁-C₂₀-alkyl radicals in general. Preference is given toC₁- to C₁₀-alkyl radicals, particular preference to C₁- to C₈-alkylradicals. The alkyl radicals may be either straight-chain or branched.In addition, the alkyl radicals may be substituted by one or moresubstituents selected from the group consisting of C₁-C₂₀-alkoxy,halogen, preferably F, and C₆-C₃₀-aryl which may in turn be substitutedor unsubstituted. Examples of suitable alkyl groups are methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl and octyl, and also isopropyl,isobutyl, isopentyl, sec-butyl, tert-butyl, neopentyl,3,3-dimethylbutyl, 2-ethylhexyl, and also derivatives of the alkylgroups mentioned substituted by C₆-C₃₀-aryl, C₁-C₂₀-alkoxy and/orhalogen, especially F, for example CF₃.

The term “aryl” or “aryl group” or “aryl radical” as used in the contextof the present invention is understood to mean optionally substitutedC₆-C₃₀-aryl radicals which are derived from monocyclic, bicyclic,tricyclic or else multicyclic aromatic rings, where the aromatic ringsdo not comprise any ring heteroatoms. The aryl radical preferablycomprises 5- and/or 6-membered aromatic rings. When the aryls are notmonocyclic systems, in the case of the term “aryl” for the second ring,the saturated form (perhydro form) or the partly unsaturated form (forexample the dihydro form or tetrahydro form), provided the particularforms are known and stable, is also possible. The term “aryl” in thecontext of the present invention thus comprises, for example, alsobicyclic or tricyclic radicals in which either both or all threeradicals are aromatic, and also bicyclic or tricyclic radicals in whichonly one ring is aromatic, and also tricyclic radicals in which tworings are aromatic. Examples of aryl are: phenyl, naphthyl, indanyl,1,2-dihydronaphthenyl, 1,4-dihydronaphthenyl, fluorenyl, indenyl,anthracenyl, phenanthrenyl or 1,2,3,4-tetrahydronaphthyl. Particularpreference is given to C₆-C₁₀-aryl radicals, for example phenyl ornaphthyl, very particular preference to C₆-aryl radicals, for examplephenyl. In addition, the term “aryl” also comprises ring systemscomprising at least two monocyclic, bicyclic or multicyclic aromaticrings joined to one another via single or double bonds. One example isthat of biphenyl groups.

The term “heteroaryl” or “heteroaryl group” or “heteroaryl radical” asused in the context of the present invention is understood to meanoptionally substituted 5- or 6-membered aromatic rings and multicyclicrings, for example bicyclic and tricyclic compounds having at least oneheteroatom in at least one ring. The heteroaryls in the context of theinvention preferably comprise 5 to 30 ring atoms. They may bemonocyclic, bicyclic or tricyclic, and some can be derived from theaforementioned aryl by replacing at least one carbon atom in the arylbase skeleton with a heteroatom. Preferred heteroatoms are N, O and S.The hetaryl radicals more preferably have 5 to 13 ring atoms. The baseskeleton of the heteroaryl radicals is especially preferably selectedfrom systems such as pyridine and five-membered heteroaromatics such asthiophene, pyrrole, imidazole or furan. These base skeletons mayoptionally be fused to one or two six-membered aromatic radicals. Inaddition, the term “heteroaryl” also comprises ring systems comprisingat least two monocyclic, bicyclic or multicyclic aromatic rings joinedto one another via single or double bonds, where at least one ringcomprises a heteroatom. When the heteroaryls are not monocyclic systems,in the case of the term “heteroaryl” for at least one ring, thesaturated form (perhydro form) or the partly unsaturated form (forexample the dihydro form or tetrahydro form), provided the particularforms are known and stable, is also possible. The term “heteroaryl” inthe context of the present invention thus comprises, for example, alsobicyclic or tricyclic radicals in which either both or all threeradicals are aromatic, and also bicyclic or tricyclic radicals in whichonly one ring is aromatic, and also tricyclic radicals in which tworings are aromatic, where at least one of the rings, i.e. at least onearomatic or one nonaromatic ring, has a heteroatom. Suitable fusedheteroaromatics are, for example, carbazolyl, benzimidazolyl,benzofuryl, dibenzofuryl or dibenzothiophenyl. The base skeleton may besubstituted at one, more than one or all substitutable positions,suitable substituents being the same as have already been specifiedunder the definition of C₆-C₃₀-aryl. However, the hetaryl radicals arepreferably unsubstituted. Suitable hetaryl radicals are, for example,pyridin-2-yl, pyridin-3-yl, pyridin-4-yl, thiophen-2-yl, thiophen-3-yl,pyrrol-2-yl, pyrrol-3-yl, furan-2-yl, furan-3-yl and imidazol-2-yl andthe corresponding benzofused radicals, especially carbazolyl,benzimidazolyl, benzofuryl, dibenzofuryl or dibenzothiophenyl.

In the context of the invention, the term “optionally substituted”refers to radicals in which at least one hydrogen radical of an alkylgroup, aryl group or heteroaryl group has been replaced by asubstituent. With regard to the type of this substituent, preference isgiven to alkyl radicals, for example methyl, ethyl, propyl, butyl,pentyl, hexyl, heptyl and octyl, and also isopropyl, isobutyl,isopentyl, sec-butyl, tert-butyl, neopentyl, 3,3-dimethylbutyl and2-ethylhexyl, aryl radicals, for example C₆-C₁₀-aryl radicals,especially phenyl or naphthyl, most preferably C₆-aryl radicals, forexample phenyl, and hetaryl radicals, for example pyridin-2-yl,pyridin-3-yl, pyridin-4-yl, thiophen-2-yl, thiophen-3-yl, pyrrol-2-yl,pyrrol-3-yl, furan-2-yl, furan-3-yl and imidazol-2-yl, and also thecorresponding benzofused radicals, especially carbazolyl,benzimidazolyl, benzofuryl, dibenzofuryl or dibenzothiophenyl. Furtherexamples include the following substituents: alkenyl, alkynyl, halogen,hydroxyl.

The degree of substitution here may vary from monosubstitution up to themaximum number of possible substituents.

Preferred compounds of the formula I for use in accordance with theinvention are notable in that at least two of the R¹, R² and R³ radicalsare para-OR and/or —NR₂ substituents. The at least two radicals here maybe only —OR radicals, only —NR₂ radicals, or at least one —OR and atleast one —NR₂ radical.

Particularly preferred compounds of the formula I for use in accordancewith the invention are notable in that at least four of the R¹, R² andR³ radicals are para-OR and/or —NR₂ substituents. The at least fourradicals here may be only —OR radicals, only —NR₂ radicals or a mixtureof —OR and —NR₂ radicals.

Very particularly preferred compounds of the formula I for use inaccordance with the invention are notable in that all of the R¹, R² andR³ radicals are para-OR and/or —NR₂ substituents. They may be only —ORradicals, only —NR₂ radicals or a mixture of —OR and —NR₂ radicals.

In all cases, the two R in the —NR₂ radicals may be different from oneanother, but they are preferably the same.

Preferably, A¹, A² and A³ are each independently selected from the groupconsisting of

in whichm is an integer from 1 to 18,R⁴ is alkyl, aryl or heteroaryl, where R⁴ is preferably an aryl radical,more preferably a phenyl radical,R⁵, R⁶ are each independently H, alkyl, aryl or heteroaryl,where the aromatic and heteroaromatic rings of the structures shown mayoptionally have further substitution. The degree of substitution of thearomatic and heteroaromatic rings here may vary from monosubstitution upto the maximum number of possible substituents.

Preferred substituents in the case of further substitution of thearomatic and heteroaromatic rings include the substituents alreadymentioned above for the one, two or three optionally substitutedaromatic or heteroaromatic groups.

Preferably, the aromatic and heteroaromatic rings of the structuresshown do not have further substitution.

More preferably, A¹, A² and A³ are each independently

more preferably

More preferably, the at least one compound of the formula (I) has one ofthe following structures

In an alternative embodiment, the organic p-type semiconductor comprisesa compound of the type ID322 having the following structure:

The compounds for use in accordance with the invention can be preparedby customary methods of organic synthesis known to those skilled in theart. References to relevant (patent) literature can additionally befound in the synthesis examples adduced below.

d) Second Electrode

The second electrode may be a bottom electrode facing the substrate orelse a top electrode facing away from the substrate. As outlined above,the second electrode may be fully or partially transparent. As usedherein, the term partially transparent refers to the fact that thesecond electrode may comprise transparent regions and intransparentregions.

One or more materials of the following group of materials may be used:at least one metallic material, preferably a metallic material selectedfrom the group consisting of aluminum, silver, platinum, gold; at leastone nonmetallic inorganic material, preferably LiF; at least one organicconductive or semiconductive material, preferably at least oneelectrically conductive polymer and, more preferably, at least onetransparent electrically conductive polymer.

The second electrode may comprise at least one metal electrode, whereinone or more metals in pure form or as a mixture/alloy, such asespecially aluminum or silver may be used.

Additionally or alternatively, nonmetallic materials may be used, suchas inorganic materials and/or organic materials, both alone and incombination with metal electrodes. As an example, the use ofinorganic/organic mixed electrodes or multilayer electrodes is possible,for example the use of LiF/Al electrodes. Additionally or alternatively,conductive polymers may be used. Thus, the second electrode of theoptical sensor preferably may comprise one or more conductive polymers.

Thus, as an example, the second electrode may comprise one or moreelectrically conductive polymers, in combination with one or more layersof a metal. Preferably, the at least one electrically conductive polymeris a transparent electrically conductive polymer. This combinationallows for providing very thin and, thus, transparent metal layers, bystill providing sufficient electrical conductivity in order to renderthe second electrode both transparent and highly electricallyconductive. Thus, as an example, the one or more metal layers, each orin combination, may have a thickness of less than 50 nm, preferably lessthan 40 nm or even less than 30 nm.

As an example, one or more electrically conductive polymers may be used,selected from the group consisting of: polyanaline (PANI) and/or itschemical relatives; a polythiophene and/or its chemical relatives, suchas poly(3-hexylthiophene) (P3HT) and/or PEDOT:PSS(poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)). Additionallyor alternatively, one or more of the conductive polymers as disclosed inEP2507286 A2, EP2205657 A1 or EP2220141 A1. For further exemplaryembodiments, reference may be made to U.S. provisional application No.61/739,173 or U.S. provisional application No. 61/708,058, the fullcontent of all of which is herewith included by reference.

In addition or alternatively, inorganic conductive materials may beused, such as inorganic conductive carbon materials, such as carbonmaterials selected from the group consisting of: graphite, graphene,carbon nano-tubes, carbon nano-wires.

In addition, it is also possible to use electrode designs in which thequantum efficiency of the components is increased by virtue of thephotons being forced, by means of appropriate reflections, to passthrough the absorbing layers at least twice. Such layer structures arealso referred to as “concentrators” and are likewise described, forexample, in WO 02/101838 (especially pages 23-24).

As outlined above, the detector comprises at least one illuminationsource to illuminate the object with illumination light through thelongitudinal optical sensor. The illumination source can be embodied invarious ways. Thus, the illumination source can be for example part ofthe detector in a detector housing. Alternatively or additionally,however, the at least one illumination source can also be arrangedoutside a detector housing, for example as a separate light source. Theillumination source can be arranged separately from the object andilluminate the object from a distance.

The illumination light preferably may have a wavelength in the infraredspectral range. The illumination source can comprise in particular oneor a plurality of the following illumination sources: a laser, inparticular a laser diode, for example an IR laser diode with outputwavelength in the infrared part of the electromagnetic spectrum,although in principle, alternatively or additionally, other types oflasers can also be used; a light emitting diode; an incandescent lamp;an organic light source, in particular an organic light emitting diode.The infrared part of the electromagnetic spectrum preferably refers to aspectral range of 780 nm to 1 mm, preferably 780 nm to 3.0 μm.Alternatively or additionally, other illumination sources can also beused. It is particularly preferred if the illumination source isdesigned to generate one or more light beams having a Gaussian beamprofile, as is at least approximately the case for example in manylasers. However, other embodiments are also possible, in principle.

As used herein, the term evaluation device generally refers to anarbitrary device designed to generate the at least one item ofinformation on the longitudinal position of the object by evaluating thelongitudinal sensor signal. As an example, the evaluation device may beor may comprise one or more integrated circuits, such as one or moreapplication-specific integrated circuits (ASICs), and/or one or moredata processing devices, such as one or more computers, preferably oneor more microcomputers and/or microcontrollers. Additional componentsmay be comprised, such as one or more preprocessing devices and/or dataacquisition devices, such as one or more devices for receiving and/orpreprocessing of the transversal sensor signal and/or the longitudinalsensor signal, such as one or more AD-converters and/or one or morefilters. Further, the evaluation device may comprise one or more datastorage devices. Further, as outlined above, the evaluation device maycomprise one or more interfaces, such as one or more wireless interfacesand/or one or more wire-bound interfaces.

Further, the at least one evaluation device may be formed as a separateevaluation device independent from the at least one longitudinal opticalsensor, but may preferably be connected to the at least one longitudinaloptical sensing order to receive the longitudinal sensor signal.Alternatively, the at least one evaluation device may fully or partiallybe integrated into the at least one longitudinal optical sensor.

The at least one evaluation device may be adapted to perform at leastone computer program, such as at least one computer program performingor supporting generating the at least one item of information on thelongitudinal position. As an example, one or more algorithms may beimplemented which, by using the longitudinal sensor signal as inputvariables, may perform a predetermined transformation into thelongitudinal position of the object. The evaluation device may compriseat least one data processing device, such as at least onemicrocontroller or processor. Thus, as an example, the at least oneevaluation device may comprise at least one data processing devicehaving a software code stored thereon comprising a number of computercommands.

The evaluation device can be connected to or may comprise at least onefurther data processing device that may be used for one or more ofdisplaying, visualizing, analyzing, distributing, communicating orfurther processing of information, such as information obtained by theoptical sensor and/or by the evaluation device. The data processingdevice, as an example, may be connected or incorporate at least one of adisplay, a projector, a monitor, an LCD, a TFT, a loudspeaker, amultichannel sound system, an LED pattern, or a further visualizationdevice. It may further be connected to or incorporate at least one of acommunication device or communication interface, a datalink, a timexdatalink, a connector or a port, capable of sending encrypted orunencrypted information using one or more of email, text messages,telephone, bluetooth, radio, Wi-Fi, infrared or internet interfaces,ports or connections. It may further be connected to or incorporate atleast one of a processor, a graphics processor, a CPU, an OpenMultimedia Applications Platform (OMAP™), an integrated circuit, asystem on a chip such as products from the Apple A series or the SamsungS3C2 series, a microcontroller or microprocessor, one or more memoryblocks such as ROM, RAM, EEPROM, or flash memory, timing sources such asoscillators or phase-locked loops, counter-timers, real-time timers, orpower-on reset generators, voltage regulators, power managementcircuits, or DMA controllers. Individual units may further be connectedby buses such as AMBA buses and/or may contain one or more transmittersand/or receivers.

The evaluation device and/or the data processing device may be connectedby or have further external interfaces or ports such as one or more ofserial or parallel interfaces or ports, USB, Centronics Port, FireWire,HDMI, Ethernet, Bluetooth, RFID, radio, datalink, Wi-Fi, USART, or SPI,or analog interfaces or ports such as one or more of ADCs or DACs, orstandardized interfaces or ports to further devices such as a 2D-cameradevice using an RGB-interface such as CameraLink. The evaluation deviceand/or the data processing device may further be connected by one ormore of interprocessor interfaces or ports, FPGA-FPGA-interfaces, orserial or parallel interfaces or ports. The evaluation device and thedata processing device may further be connected to one or more of anoptical disc drive, a CD-RW drive, a DVD+RW drive, a flash drive, amemory card, a disk drive, a hard disk drive, a solid state disk or asolid state hard disk.

The evaluation device and/or the data processing device may be connectedby or have one or more further external connectors such as one or moreof phone connectors, RCA connectors, VGA connectors, hermaphroditeconnectors, USB connectors, HDMI connectors, 8P8C connectors, BCNconnectors, IEC 60320 C14 connectors, optical fiber connectors,D-subminiature connectors, RF connectors, coaxial connectors, SCARTconnectors, XLR connectors, and/or may incorporate at least one suitablesocket for one or more of these connectors.

Possible embodiments of a device such as a single device incorporatingone or more of the detectors according to the present invention, theevaluation device or the data processing device, such as incorporatingone or more of the optical sensor, optical systems, evaluation device,communication device, data processing device, interfaces, system on achip, display devices, or further electronic devices, are: mobilephones, personal computers, tablet PCs, televisions, game consoles orfurther entertainment devices. In a further embodiment, the 3D-camerafunctionality which will be outlined in further detail below may beintegrated in devices that are available with conventional 2D-digitalcameras, without a noticeable difference in the housing or appearance ofthe device, where the noticeable difference for the user may only be thefunctionality of obtaining and or processing 3D information.

Specifically, an embodiment incorporating the detector and/or a partthereof such as the evaluation device and/or the data processing devicemay be: a mobile phone incorporating a display device, a data processingdevice, the optical sensor, optionally the sensor optics, and theevaluation device, for the functionality of a 3D camera. The detectoraccording to the present invention specifically may be suitable forintegration in entertainment devices and/or communication devices suchas a mobile phone.

A further embodiment of the present invention may be an incorporation ofthe detector or a part thereof such as the evaluation device and/or thedata processing device in a device for use in automotive, for use inautonomous driving or for use in car safety systems such as Daimler'sIntelligent Drive system, wherein, as an example, a device incorporatingone or more of the optical sensors, optionally one or more opticalsystems, the evaluation device, optionally a communication device,optionally a data processing device, optionally one or more interfaces,optionally a system on a chip, optionally one or more display devices,or optionally further electronic devices may be part of a vehicle, acar, a truck, a train, a bicycle, an airplane, a ship, a motorcycle. Inautomotive applications, the integration of the device into theautomotive design may necessitate the integration of the optical sensor,optionally optics, or device at minimal visibility from the exterior orinterior. The detector or a part thereof such as the evaluation deviceand/or the data processing device may be especially suitable for suchintegration into automotive design.

As outlined above, the at least one illumination source is adapted toilluminate the at least one object with illumination light. In additionto illuminating the at least one object with illumination light throughthe longitudinal optical sensor, the at least one illumination sourcemay, additionally or alternatively, further be adapted to illuminate theat least one object in other ways, such as by illumination light whichis not transmitted through the at least one longitudinal optical sensor.Thus, at least one illumination source may be placed outside a beam pathof the detector, in order to illuminate the at least one object in anoff-axis fashion.

The illumination light generally, in case an illumination through thelongitudinal optical sensor takes place and/or in case a different typeof illumination is used, optionally may imply at least one reflection ofthe illumination light before the illumination light illuminates the atleast one object. Thus, generally, the detector may further comprise atleast one reflective element, wherein the reflective element is adaptedto reflect the illumination light before illuminating the object. Theuse of at least one reflective element generally implies severaladvantages. Thus, generally, by using at least one reflective element,an adjustment of an orientation of the illumination light, such as anillumination light beam, may be performed by adjusting the at least onereflective element. Further, the at least one reflective element, aswill be outlined in further detail below, may be a wavelength-selectivereflective element, the reflection properties of which may depend on thewavelength. Thus, generally, the wavelength-selective reflective elementmay be or may comprise at least one infrared reflective element whichexhibits reflective properties in the infrared spectral region, whereas,in other spectral regions such as the visible spectral region, noreflective properties or significantly lower reflective properties ascompared to the infrared spectral region may be present. Thus,generally, the at least one illumination source may comprise at leastone infrared illumination source for illuminating the at least oneobject with infrared illumination light, and the at least one reflectiveelement may comprise at least one reflective element exhibitingreflective properties in the infrared spectral region, such as aso-called “hot” mirror.

When illuminating the at least one object with illumination light, be itthrough the at least one longitudinal optical sensor and/or be it in adifferent fashion, the at least one illumination light may be fixed indirection and/or space and/or may be adjustable or movable in directionand/or space. Thus, as an example, the reflective element may be or maycomprise at least one movable reflective element adapted to be adjustedto at least two different positions, wherein, in the at least twodifferent positions, the illumination light is reflected into differentdirections. As used herein, the term “position” generally may refer toany type of absolute position and/or any type of orientation of themovable mirror. Thus, at least one longitudinal translation of themovable mirror and/or at least one rotational movement of the at leastone movable mirror may be feasible.

Thus, as an example, the at least one movable reflective element may bea reflective element the orientation of which may be adjusted to atleast one first orientation and at least one second orientation beingdifferent from the at least one first orientation. The adjustment maytake place in a stepwise or a continuous fashion.

In case the at least one reflective element comprises at least onemovable reflective element, the movable reflective element may be asingle movable reflective element or may be or may comprise a pluralityof movable reflective elements. Thus, the at least one reflectiveelement may comprise a plurality of movable reflective elements, such asa plurality of movable mirrors, preferably a plurality of micro-mirrors.Thus, as an example, the at least one movable reflective element maycomprise a plurality of micro-mirrors, specifically an area ofmicro-mirrors, such as micro-mirrors based on piezo technology. As anexample, micro-mirrors as used in projection technology may be used,such as micro-mirrors available for beamers or other types ofprojectors. As an example, digital light processing (DLP®) technology,such as the light processing technology available from TexasInstruments, may be used. More specifically, at least one DLP®-chip maybe used. More generally, a reflective spatial light modulator may beused and/or the at least one movable reflective element may comprise atleast one reflective spatial light modulator.

By using a plurality of movable reflective elements, the illuminationlight may be subdivided into a plurality of illumination light beams,the position/orientation of which, preferably, may individually becontrolled by the plurality of movable reflective elements. Thereby, asan example, a projection of various patterns and/or a modulation ofpoints and/or patterns of the illumination light beams are feasible. Incase a plurality of movable reflective elements is used, an individualcontrol of the movable reflective elements may take place, such as anindividual control at different control frequencies. Thereby, anillumination of the at least one object by the plurality of illuminationlight beams and/or by a pattern of illumination light beams at differentfrequencies is feasible. Consequently, the illumination may take placein a modulated fashion, such as by periodically controlling the movablereflective element at different modulation frequencies. The illuminationmay then be resolved by the detector, such as by the one or moreFiP-sensors contained therein, such as by demodulating one or more ofthe detector signals and/or by a frequency analysis.

By using a plurality, specifically an array, of movable reflectiveelements, specifically an array of mirrors and/or a reflective spatiallight modulator, and more specifically a DLP® array, a projection ofillumination light patterns may be performed, such as for projectinggeneric patterns and/or specialized patterns into a field of view of thedetector, such as for covering a complete or partial measurement spaceof the detector.

Further, by using the plurality of movable reflective elements, morespecifically an array of movable reflective elements, such as an arrayof mirrors, a reflective spatial light modulator and/or a DLP® array,the plurality of movable reflective elements may be used for projectingpoints and/or patterns of the illumination light into space,specifically into a field of view of the detector, such as into an imageof a camera, specifically for following one or more specific objects inspace, such as for following limbs, toys or other object or partsthereof.

In case a pattern and/or array of the movable reflective element isused, such as one or more DLP® chips, the pattern itself may be ageneric pattern or may be a dedicated pattern for the detector, such asa pattern dependent on a RGB-camera picture.

In case the at least one reflective element is or comprises at least onemovable reflective element, the at least one movable reflective elementmay be adapted to scan the illumination light through at least one scanregion in space. Again, the scanning process may take place in acontinuous fashion or in a stepwise fashion. Thus, as an example, the atleast one movable reflective element may comprise at least one movablemirror, such as a galvo-scanner or any other type of movable mirror, theposition and/or orientation of which may be adjusted.

In case at least one movable reflective element is used, the adjustmentof the at least one movable reflective element may take place in amanual fashion and/or in an automatic fashion. Thus, as an example, theat least one detector may comprise at least one actuator adapted foradjusting the position of the at least one movable mirror. As anexample, the at least one actuator may be or may comprise at least oneadjustment screw and/or at least one other type of actuator, such as atleast one piezo actuator.

As outlined above, the illumination source generally and specificallymay be adapted to emit illumination light in one or more of the visiblespectral range, the infrared spectral range and the ultraviolet spectralrange. Specifically, the illumination light may be illumination light inthe infrared spectral range. Thus, as outlined above, the reflectiveelement may be adapted to reflect light in the infrared spectral range,wherein light in the visible spectral range is transmitted. Othercombinations of reflective properties in the different spectral rangesare feasible. Specifically, the at least one reflective element maycomprise at least one movable reflective element having reflectiveproperties in the infrared spectral range, such as a movable infraredmirror, specifically a movable “hot” mirror.

The at least one reflective element generally may be an arbitraryelement adapted to fully or partially reflect or redirect theillumination light in space. As the skilled person will recognize,various types of reflective elements are generally known and may be usedherein. Specifically, the reflective element may be selected from thegroup consisting of: a mirror; a semitransparent mirror; a mirror orsemi-transparent mirror reflecting only specific spectral regions, suchas light in the infrared spectral range; a prism; a dichroitic mirror; abeam splitter cube. Combinations of the named elements and/or othertypes of reflective elements are feasible. Specifically, as will beoutlined in further detail below, the at least one reflective elementmay exhibit beam-splitting properties, and, thus, the at least onereflective element, be it a rigid reflective element or a movablereflective element, may fully or partially be identical to at least onebeam-splitting device which may be present in the detector.

The use of at least one reflective element, specifically the use of atleast one movable reflective element, more specifically the use of atleast one movable reflective element having reflective properties in theinfrared spectral range, provides a large number of advantages, aspartially outlined above. Thus, as an example, current distance sensorsas commercially available e.g. in the field of gaming, generally mayproject a point pattern into the space to be analyzed. The point patternmay be monitored by using at least one camera, and appropriatemeasurement algorithms may be applied. This process requires asignificant amount of computing power. Contrarily, the detectoraccording to the present invention, provides an easy way of simplifyingthe detection process. The illumination light, such as infraredillumination light, more specifically a single infrared light beam, maybe moved through the space to be analyzed, by using the movablereflective element such as a movable infrared mirror. In this setup, therequired computational resources may significantly be reduced ascompared to conventional detectors.

Thus, as outlined above, a scanning process may be applied. The movablemirror allows for reading out e.g. line patterns, square patterns orother patterns. Thus, the detector, specifically the detector comprisingone or more longitudinal optical sensors, more specifically comprisingone or more organic solar cells and/or DSCs and/or sDSCs, may provide adirect and fast longitudinal information such as a distance information.The movable reflective element, such as the movable mirror, generallymay be adapted for tracking the at least one object by adjusting the atleast one position of the at least one movable reflective elementaccording to the position of the object. Thereby, the detector may beadapted for tracking and/or analyzing specific objects, such as humans,faces, limbs or other movable objects or combinations of movable object.

The at least one object may comprise or may be combined with at leastone beacon device, also referred to as a target device, which may beadapted to emit at least one light beam and/or to transmit at least onelight beam towards the detector. For potential embodiments of the atleast one beacon device, reference may be made e.g. to WO 2012/110924A1. Other embodiments are feasible. Thus, generally, the at least onebeacon device may be or may comprise at least one passive beacon deviceadapted to reflect light such as the illumination light and/or may be ormay comprise at least one active device adapted for emitting light.Thus, generally, one or more actively emitting target devices and/orreflecting targets devices may be used, specifically in combination witha movable reflective device. In the setup, as an example, a movableinfrared light beam may be used as illumination light and/or as a partof the illumination light, and the detector may be adapted to measurepatterns and/or specific regions in space and/or may be adapted to trackspecific objects.

As will be outlined in further detail below, the detector may furthercomprise at least one imaging device such as at least one camera, morespecifically a full-color camera such as an RGB-camera. In this setup,the movable infrared illumination light, such as the movable infraredlight beam may be used in order to analyze regions in the RGB-picturethat appear specifically important, such as moving and/or changingobjects. This feature may be achieved via simple picture analysisalgorithms. Thereby, a fast and simple tracking of faces, limbs or othermovable and objects may be feasible.

In the context of gaming, as will be outlined in further detail below,such as in the context of game consoles and/or augmented realityapplications, the detector according to the present invention,specifically having the at least one movable reflective element,provides additional advantages. Thus, current sensors are generallyincapable of analyzing object in space. Consequently, these types ofsensors generally are limited in their interpretation of the augmentedreality information. Thus, commercially available sensors and detectorsgenerally are incapable of analyzing depth information. These sensors ordetectors are capable of detecting a 2D position. However, since nodepth information of objects such as hands, feet or other body parts areavailable, the augmented reality generally is influenced by the2D-image, only. Contrarily, in the context of the present invention, atracking of objects in space becomes feasible, specifically in thecontext of machine control, gaming or augmented reality. Still, asoutlined above, the invention may be performed by using standardcomputational resources or, generally, low computational resources low.

The detector further may comprise at least one imaging device. Theimaging device may be adapted such that the light beam traveling fromthe object to the detector passes through with the longitudinal opticalsensor before impinging on the imaging device.

As used herein, an imaging device is generally understood as a devicewhich can generate a one-dimensional, a two-dimensional, or athree-dimensional image of the object or of a part thereof. Inparticular, the imaging device can be completely or partly used as acamera. For example, the imaging device may be a camera selected fromthe group consisting of: an RGB camera, i.e. a camera which is designedto deliver three basic colors which are designated as red, green, andblue, on three separate connections; an IR camera, i.e. a camera whichis designed to record parts of the light beam in the infrared spectralrange; although in principle, alternatively or additionally, other typesof cameras can also be used. Other embodiments of the imaging device arealso possible.

The imaging device may be designed to image a plurality of partialregions of the object successively and/or simultaneously. By way ofexample, a partial region of the object can be a one-dimensional, atwo-dimensional, or a three-dimensional region of the object which isdelimited for example by a resolution limit of the imaging device andfrom which electromagnetic radiation emerges.

In this context, imaging should be understood to mean that theelectromagnetic radiation which emerges from the respective partialregion of the object is fed into the imaging device, for example bymeans of at least one optional transfer device of the detector.

In particular, the imaging device can be designed to image sequentially,for example by means of a scanning method, in particular using at leastone row scan and/or line scan, the plurality of partial regionssequentially. However, other embodiments are also possible, for exampleembodiments in which a plurality of partial regions is simultaneouslyimaged. The imaging device is designed to generate, during this imagingof the partial regions of the object, signals, preferably electronicsignals, associated with the partial regions. The signal may be ananalogue and/or a digital signal. By way of example, an electronicsignal can be associated with each partial region. The electronicsignals can accordingly be generated simultaneously or else in atemporally staggered manner. By way of example, during a row scan orline scan, it is possible to generate a sequence of electronic signalswhich correspond to the partial regions of the sample, which are strungtogether in a line, for example. Further, the imaging device maycomprise one or more signal processing devices, such as one or morefilters and/or analogue-digital-converters for processing and/orpreprocessing the electronic signals.

The imaging device may comprise a camera chip, for example a CCD chipand/or CMOS chip. Preferably, the imaging device may comprise aninorganic imaging device. The imaging device may comprise a matrix ofpixels. As used herein, a pixel generally refers to a light-sensitiveelement of the imaging device. As used here, a “matrix” generally refersto an arrangement of a plurality of the pixels in space, which may be alinear arrangement or an areal arrangement. Thus, generally, the matrixpreferably may be selected from the group of: a one-dimensional matrix;a two-dimensional matrix. Most preferably, the matrix is a rectangularmatrix having pixels arranged in rows and columns. The imaging devicemay comprise a chip selected from the group consisting of a CMOS chipand a CCD chip. Further the imaging device may be adapted to resolvecolors. The imaging device may be a full-color CCD chip. In a preferredembodiment, the imaging device may be an RGB camera and/or an IR camera.

The detector further may comprise at least one beam-splitting device,wherein the beam splitting device may be adapted to separate theillumination light emitted by the illumination source before passing thelongitudinal optical sensor from the light beam traveling from theobject to the detector after passing the longitudinal optical sensor. Asused here, a beam splitting device is a device adapted to split thelight beam emitted by the illumination device into two or more lightbeams and to deflect the light beam in the direction of the opticalaxis, in particular parallel to the direction of the optical axis. Thebeam splitting device may be selected from the group consisting of: asemitransparent mirror; a mirror or semi-transparent mirror reflectingonly specific spectral regions, such as light in the infrared spectralrange; a prism; a dichroitic mirror; a beam splitter cube.

As outlined above, the at least one optional beam-splitting device mayfully or partially be identical with the at least one optionalreflective element. Thus, as outlined above, the beam-splitting devicemay be or may comprise at least one movable reflective element adaptedto be adjusted to at least two different positions, wherein, in the atleast two different positions, the illumination light is reflected intodifferent directions. Specifically, the at least one beam-splittingdevice may be or may comprise at least one infrared reflective element,more specifically at least one movable infrared reflective element.

Therein, the position and/or orientation of the at least one light beamtraveling from the object to the detector after passing the longitudinaloptical sensor may be kept at least substantially unchanged when passingthe at least one reflective element, specifically when passing the atleast one movable reflective element. Thus, specifically, the at leastone movable reflective element may be adapted such that, when moving themovable reflective element, a position and/or orientation of theillumination light is changed by the movement of the movable reflectiveelement, whereas a position and/or orientation of the light beam may bekept at least substantially independent from the movement of the movablereflective element.

The longitudinal sensor signal may further dependent on a modulationfrequency of the light beam. In particular, the FiP-effect may depend onor may be emphasized by an appropriate modulation of the light beam, asdisclosed in WO 2012/110924 A1. Specifically in case the at least onelongitudinal optical sensor provides the above-mentioned FiP-effect, thesensor signal of longitudinal the optical sensor may be dependent on amodulation frequency of the light beam. As an example, the FiP-effectmay function as modulation frequencies of 0.1 Hz to 10 kHz.

The illumination source may be adapted to periodically modulate at leastone optical property of the illumination light. Thus, the illuminationsource may be adapted to emit the light beam in a modulated way and/oran additional modulation device, which may be adapted to periodicallymodulated at least one optical property of the illumination light, maybe used. For example, the at least one optical property may be selectedfrom the group consisting of an amplitude and a phase of theillumination light. The modulation may be used for one or more differentpurposes, such as for enhancing and/or enabling the FiP-effect and/orfor identifying one or more illumination sources emitting at a specificmodulation frequency. The latter purpose may be used for distinguishingbetween two or more different modulated light beams at differentmodulation frequencies. For further details, reference may be made to EP13171900.7, filed on Jun. 13, 2013.

The illumination source is adapted to send out at least two light beamshaving differing optical properties. For example, the at least two lightbeams may have a differing spectral property. For example, the spectralproperty of the light beams may be a color and/or a polarization of theportion of the light beam. Preferably, the at least two light beams aremodulated with different modulation frequencies.

The evaluation device preferably may be adapted for performing thefrequency analysis by demodulating the longitudinal sensor signal withdifferent modulation frequencies. The modulation of the light beams sendout by the illumination source and the demodulation of the longitudinalsensor signals by the evaluation device preferably take place with thesame set of modulation frequencies. For this purpose, the evaluationdevice may contain one or more demodulation devices, such as one or morefrequency mixing devices, one or more frequency filters such as one ormore low-pass filters or one or more lock-in amplifiers and/orFourier-analyzers. The evaluation device preferably may be adapted toperform a discrete or continuous Fourier analysis over a predeterminedand/or adjustable range of frequencies.

The evaluation device may comprise one or more electronic components,such as one or more frequency mixing devices and/or one or more filters,such as one or more band-pass filters and/or one or more low-passfilters. Thus, as an example, the evaluation device may comprise atleast one lock-in amplifier or, preferably, a set of lock-in amplifiers,for performing the frequency analysis. Thus, as an example, in case aset of modulation frequencies is provided, the evaluation device maycomprise a separate lock-in amplifier for each modulation frequency ofthe set of modulation frequencies or may comprise one or more lock-inamplifiers adapted for performing a frequency analysis for two or moreof the modulation frequencies, such as sequentially or simultaneously.Lock-in amplifiers of this type generally are known in the art.

The evaluation device may be designed to generate the at least one itemof information on the longitudinal position of the object from at leastone predefined relationship between the geometry of the illumination ofthe sensor region by the light beam and a relative positioning of theobject with respect to the detector. The predefined relationship betweenthe geometry of the illumination of the sensor region by the light beamand the relative positioning of the object with respect to the detectormay take account of a known power of the illumination. The knownrelationship may be stored in the evaluation device as an algorithmand/or as one or more calibration curves. As an example, specificallyfor Gaussian beams, a relationship between a beam diameter or a beamwaist and a position of the object may easily be derived by using theGaussian relationship between the beam waist and a longitudinalcoordinate. The predefined relationship between the geometry of theillumination of the sensor region by the light beam and the relativepositioning of the object with respect to the detector may take accountof a modulation frequency with which the illumination is modulated.

The detector may comprise at least one optical device, wherein theoptical device comprises at least one element having one or both of afocusing or a defocusing effect onto at least one of the illuminationlight and the light beam. The optical device is also referred to astransfer device. The at least one optical device may fully or partiallybe positioned in one or more of the following positions

-   -   In a beam path in between the illumination source and the        longitudinal optical sensor;    -   In a beam path between the longitudinal optical sensor and the        object;    -   In a beam path in between the longitudinal optical sensor and an        imaging device adapted such that the light beam traveling from        the object to the detector passes through the longitudinal        optical sensor before passing the optical device and impinging        on the imaging device. As used herein, the term “beam path”        refers to the path on which the light beam travels. The optical        device may comprise at least one element selected from the group        consisting of: a focusing lens; a defocusing lens; a camera        lens; a curved mirror; a diaphragm.

The illumination light may travel at least partially substantiallyparallel to the optical axis of the detector. As used herein, the term“substantially parallel” refers to a beam axis which deviates not morethan ±20°, preferably not more than ±10°, more preferably not more than±5°, from the optical axis. The longitudinal optical sensor, theillumination source and, optionally, the imaging device are arrangedcoaxially with regard to the optical axis of the detector.

In devices known from prior art, one or more of the components selectedfrom the group consisting of the illumination source, the longitudinaloptical sensor and optionally, the imaging device has to be displacedfrom the optical axis defined by the optical axis of the longitudinaloptical sensor, because of the opacity of the devices. The proposedalignment of the longitudinal optical sensor, the illumination source anoptionally, the imaging device is advantageous because it may bepossible to make the detector more compact and, thus, less expensivewith respect to detectors known from prior art.

Further, the displacement of the components selected from the groupconsisting of the illumination source, the imaging device and thelongitudinal optical sensor may result in parallaxes problems, becausethe object may be illuminated by the illumination source by lighttravelling along a different optical axis with respect to the opticalaxis defined by the longitudinal optical sensor. In addition, the objectmay be viewed along different lines of sight by the longitudinal sensorand the optional imaging detector. In contrast, because of thetransparency of the longitudinal optical detector, the proposedalignment of the illumination source, the longitudinal optical sensor,and optionally the imaging device, on one common optical axis defined bythe optical axis of the longitudinal optical sensor is possible. Lighttravelling from the illumination source may illuminate the at least oneobject and may impinge the longitudinal optical sensor and the imagingdevice on the common optical axis. Thus, the object is viewed on oneline of sight and such no parallaxes occur.

Further, in devices known from prior art, due to the displacement of theillumination source from the optical axis, defined by the optical axisof the longitudinal optical sensor, shadows, i.e. regions notilluminated by the illumination source but detectable by thelongitudinal optical sensor, may occur. The proposed alignment of theillumination source and the longitudinal optical sensor, and optionallythe imaging device on the common optical axis, may prevent theappearance of shadows, since regions illuminated by the illuminationsource and detectable by the longitudinal optical sensor are inparticular predominantly identical, more particular strictly identical.

The longitudinal optical sensor may comprise at least one semiconductordetector. In case a plurality of longitudinal optical sensors isprovided, one or more of the longitudinal optical sensors preferably maybe or may comprise at least one organic semiconductor detector and/or atleast one inorganic semiconductor detector. Most preferably, thesemiconductor detector may be an organic semiconductor detectorcomprising at least one organic material. Still, other embodiments arefeasible. Thus, combinations of one or more organic semiconductordetectors and/or one or more inorganic semiconductor detectors arefeasible. Preferably, the semiconductor detector may be selected fromthe group consisting of an organic solar cell, a dye solar cell, adye-sensitized solar cell, a solid dye solar cell, a soliddye-sensitized solar cell.

In a preferred embodiment, the illumination source, one lens and/or alens system and the longitudinal optical sensor and/or a stack oflongitudinal optical sensors may be arranged on one axis. This alignmentmay allow making the detector compact and less expensive. The lighttravelling from the illumination source to the object may impinge andpass the longitudinal optical sensor, which may generate a longitudinalsensor signal. Then the light may be reflected by the object and willimpinge on the longitudinal optical sensor again. The longitudinalsensor signal may change due to the impinging light travelling from theobject to the longitudinal optical sensor. The change in thelongitudinal sensor signal may allow to determine the position of the atleast one object.

In a further preferred embodiment, for simultaneously determining theposition of the at least one object and recording images, for examplecolor videos, the longitudinal optical sensor may be arranged in frontof an imaging device, for example a RGB camera. In this embodiment, theillumination source, for example a focused IR lamp, may be arrangeddisplaced from the common optical axis, because of the opacity of theimaging device and the illumination source. The illumination light maybe transferred to the common axis by mirrors which may be configured toreflect light in the infrared range of the electromagnetic spectrum andare light transmissive for light in the visible range of theelectromagnetic spectrum. The infrared part of the electromagneticspectrum generally refers to a spectral range of 780 nm to 1 mm,preferably 780 nm to 3.0 μm. The visible range of the electromagneticspectrum generally refers to a spectral range of 380 nm to 780 nm,preferably 380 nm to 640 nm.

In a further embodiment the detector may be used to determine more thanone position of one or more objects. The illumination source may beconfigured to emit several concentrated light beams, each modulated witha different modulation frequency. The determined longitudinal sensorsignal may be evaluated by Fourier transformation. Thus, it may bepossible to determine the contribution of each illuminated point and/orregion of the object with the same longitudinal optical sensor by usingFourier transformation.

Further, the detector, in particular the longitudinal optical sensor,may be configured to determine an x- and/or y-coordinate of the object.Thus, as outlined above, the detector may comprise one or moretransversal optical sensors.

In a further aspect of the present invention, a human-machine interfacefor exchanging at least one item of information between a user and amachine is disclosed. The human-machine interface comprises at least onedetector according to the present invention, such as according to one ormore of the embodiments disclosed above or disclosed in further detailbelow. The human-machine interface is designed to determine at least oneposition of the user by means of the detector system and is designed toassign to the position at least one item of information.

As used herein, the term “human-machine interface” generally refers toan arbitrary device or combination of devices adapted for exchanging atleast one item of information, specifically at least one item ofelectronic information, between a user and a machine such as a machinehaving at least one data processing device. The generation of the itemof information may be effected by a body posture and/or a movement of auser. The exchange of information may be performed in a unidirectionalfashion and/or in a bidirectional fashion. Specifically, thehuman-machine interface may be adapted to allow for a user to provideone or more commands to the machine in a machine-readable fashion.

In a further aspect of the invention, an entertainment device forcarrying out at least one entertainment function is disclosed. Theentertainment device comprises at least one human-machine interfaceaccording to the present invention, such as disclosed in one or more ofthe embodiments disclosed above or disclosed in further detail below.The entertainment device is designed to enable at least one item ofinformation to be input by player, i.e. a user using the entertainmentdevice for entertainment purposes, by means of the human-machineinterface, wherein the entertainment device is designed to vary theentertainment function in accordance with the information.

As used herein, an “entertainment device” is a device which may servethe purpose of leisure and/or entertainment of one or more users, in thefollowing also referred to as one or more players. As an example, theentertainment device may serve the purpose of gaming, preferablycomputer gaming. Additionally or alternatively, the entertainment devicemay also be used for other purposes, such as for exercising, sports,physical therapy or motion tracking in general. Thus, the entertainmentdevice may be implemented into a computer, a computer network or acomputer system or may comprise a computer, a computer network or acomputer system which runs one or more gaming software programs.

The entertainment device comprises at least one human-machine interfaceaccording to the present invention, such as according to one or more ofthe embodiments disclosed above and/or according to one or more of theembodiments disclosed below. The entertainment device is designed toenable at least one item of information to be input by a player by meansof the human-machine interface. The at least one item of information maybe transmitted to and/or may be used by a controller and/or a computerof the entertainment device.

The at least one item of information preferably may comprise at leastone command adapted for influencing the course of a game. Thus, as anexample, the at least one item of information may include at least oneitem of information on at least one orientation of the player and/or ofone or more body parts of the player, thereby allowing for the player tosimulate a specific position and/or orientation and/or action requiredfor gaming. As an example, one or more of the following movements may besimulated and communicated to a controller and/or a computer of theentertainment device: dancing; running; jumping; swinging of a racket;swinging of a bat; swinging of a club; pointing of an object towardsanother object, such as pointing of a toy gun towards a target.

The entertainment device as a part or as a whole, preferably acontroller and/or a computer of the entertainment device, is designed tovary the entertainment function in accordance with the information.Thus, as outlined above, a course of a game might be influenced inaccordance with the at least one item of information. Thus, theentertainment device might include one or more controllers which mightbe separate from the evaluation device of the at least one detectorand/or which might be fully or partially identical to the at least oneevaluation device or which might even include the at least oneevaluation device. Preferably, the at least one controller might includeone or more data processing devices, such as one or more computersand/or microcontrollers.

In a further aspect of the present invention, a tracking system fortracking a position of at least one movable object is disclosed. Thetracking system comprises at least one detector according to the presentinvention, such as disclosed in one or more of the embodiments givenabove or given in further detail below. The tracking system furthercomprises at least one track controller, wherein the track controller isadapted to track a series of positions of the object at specific pointsin time. For example the series of positions of the object may betracked by recording groups of data or data pairs, each group of data ordata pair comprising at least one position information and at least onetime information.

The track controller may be adapted to determine from the series ofpositions a movement of the object.

As used herein, a “tracking system” is a device which is adapted togather information on a series of past positions of the at least oneobject and/or at least one part of the object. Additionally, thetracking system may be adapted to provide information on at least onepredicted future position and/or orientation of the at least one objector the at least one part of the object. The tracking system may have atleast one track controller, which may fully or partially be embodied asan electronic device, preferably as at least one data processing device,more preferably as at least one computer or microcontroller. Again, theat least one track controller may fully or partially comprise the atleast one evaluation device and/or may be part of the at least oneevaluation device and/or may fully or partially be identical to the atleast one evaluation device.

The tracking system may be adapted to initiate one or more actions ofthe tracking system itself and/or of one or more separate devices. Forthe latter purpose, the tracking system, preferably the trackcontroller, may have one or more wireless and/or wire-bound interfacesand/or other types of control connections for initiating at least oneaction. Preferably, the at least one track controller may be adapted toinitiate at least one action in accordance with at least one actualposition of the object. As an example, the action may be selected fromthe group consisting of: a prediction of a future position of theobject; pointing at least one device towards the object; pointing atleast one device towards the detector; illuminating the object;illuminating the detector.

As an example of application of a tracking system, the tracking systemmay be used for continuously pointing at least one first object to atleast one second object even though the first object and/or the secondobject might move. Potential examples, again, may be found in industrialapplications, such as in robotics and/or for continuously working on anarticle even though the article is moving, such as during manufacturingin a manufacturing line or assembly line. Additionally or alternatively,the tracking system might be used for illumination purposes, such as forcontinuously illuminating the object by continuously pointing anillumination source to the object even though the object might bemoving. Further applications might be found in communication systems,such as in order to continuously transmit information to a moving objectby pointing a transmitter towards the moving object.

In a further aspect of the present invention, a camera for imaging atleast one object is disclosed. The camera comprises at least onedetector according to the present invention, such as disclosed in one ormore of the embodiments given above or given in further detail below.

Thus, specifically, the present application may be applied in the fieldof photography. Thus, the detector may be part of a photographic device,specifically of a digital camera. Specifically, the detector may be usedfor 3D photography, specifically for digital 3D photography. Thus, thedetector may form a digital 3D camera or may be part of a digital 3Dcamera. As used herein, the term “photography” generally refers to thetechnology of acquiring image information of at least one object. Asfurther used herein, a “camera” generally is a device adapted forperforming photography. As further used herein, the term “digitalphotography” generally refers to the technology of acquiring imageinformation of at least one object by using a plurality oflight-sensitive elements adapted to generate electrical signalsindicating an intensity and/or color of illumination, preferably digitalelectrical signals. As further used herein, the term “3D photography”generally refers to the technology of acquiring image information of atleast one object in three spatial dimensions. Accordingly, a 3D camerais a device adapted for performing 3D photography. The camera generallymay be adapted for acquiring a single image, such as a single 3D image,or may be adapted for acquiring a plurality of images, such as asequence of images. Thus, the camera may also be a video camera adaptedfor video applications, such as for acquiring digital video sequences.

Thus, generally, the present invention further refers to a camera,specifically a digital camera, more specifically a 3D camera or digital3D camera, for imaging at least one object. As outlined above, the termimaging, as used herein, generally refers to acquiring image informationof at least one object. The camera comprises at least one detectoraccording to the present invention. The camera, as outlined above, maybe adapted for acquiring a single image or for acquiring a plurality ofimages, such as image sequence, preferably for acquiring digital videosequences. Thus, as an example, the camera may be or may comprise avideo camera. In the latter case, the camera preferably comprises a datamemory for storing the image sequence.

As used within the present invention, the expression “position”generally refers to at least one item of information regarding one ormore of an absolute position and an orientation of one or more points ofthe object. Thus, specifically, the position may be determined in acoordinate system of the detector, such as in a Cartesian coordinatesystem. Additionally or alternatively, however, other types ofcoordinate systems may be used, such as polar coordinate systems and/orspherical coordinate systems.

In a further aspect of the present invention, a method for determining aposition of at least one object is disclosed, specifically a method fordetermining a position of at least one object. The method comprises thefollowing steps, which may be performed in the given order or in adifferent order. Further, two or more or even all of the method stepsmay be performed simultaneously and/or overlapping in time. Further,one, two or more or even all of the method steps may be performedrepeatedly. The method may further comprise additional method steps. Themethod comprises the following method steps:

-   -   using at least one longitudinal optical sensor of a detector,        wherein the longitudinal optical sensor has at least one sensor        region, wherein the longitudinal optical sensor is at least        partially transparent, wherein the longitudinal optical sensor        generates at least one longitudinal sensor signal in a manner        dependent on an illumination of the sensor region by at least        one light beam traveling from the object to the detector,        wherein the longitudinal sensor signal, given the same total        power of the illumination, is dependent on a beam cross-section        of the light beam in the sensor region;    -   illuminating the object with illumination light through the        longitudinal optical sensor by using at least one illumination        source; and    -   generating at least one item of information on a longitudinal        position of the object by evaluating the longitudinal sensor        signal by using at least one evaluation device.

The method preferably may be performed by using the detector accordingto the present invention, such as disclosed in one or more of theembodiments given above or given in further detail below. Thus, withregard to definitions and potential embodiments of the method, referencemay be made to the detector. Still, other embodiments are feasible.

In the generation step, the item of information on the longitudinalposition may be generated by considering an input signal of theillumination source. The illumination light may travel from theillumination source to the object and may impinge on its path on a sideof the longitudinal optical detector facing the illumination source. Thelongitudinal detector may generate a longitudinal sensor signaldependent on the power of the impinging illumination light to which itis referred to as input signal of the illumination source. Theillumination light may pass through the longitudinal optical sensor andmay illuminate the at least one object, which may reflect theillumination light. The reflected light may travel back to thelongitudinal optical sensor and may impinge on its path on the otherside of the longitudinal optical detector facing the object. Thelongitudinal detector may generate a longitudinal sensor signaldependent on the power of the impinging reflected light. The at leastone item of information on the longitudinal position of the object maybe generated from the longitudinal sensor signal. For this, the inputsignal of the illumination source may be subtracted from thelongitudinal sensor signal.

In a further aspect of the present invention, a use of the detectoraccording to the present invention, such as disclosed in one or more ofthe embodiments discussed above and/or as disclosed in one or more ofthe embodiments given in further detail below, is disclosed, for apurpose of use, selected from the group consisting of: a positionmeasurement in traffic technology; an entertainment application; asecurity application; a human-machine interface application; a trackingapplication; a photography application; a mapping application forgenerating maps of at least one space, such as at least one spaceselected from the group of a room, a building and a street; a use incombination with at least one time-of-flight measurement.

Thus, generally, the detector according to the present invention may beapplied in various fields of uses. Specifically, the detector may beapplied for a purpose of use, selected from the group consisting of: aposition measurement in traffic technology; an entertainmentapplication; a security application; a human-machine interfaceapplication; a tracking application; a photography application; amapping application for generating maps of at least one space, such asat least one space selected from the group of a room, a building and astreet; a mobile application; an optical head-mounted display; a webcam;an audio device; a dolby surround audio system; a computer peripheraldevice; a gaming application; a camera or video application; a securityapplication; a surveillance application; an automotive application; atransport application; a medical application; a sports' application; amachine vision application; a vehicle application; an airplaneapplication; a ship application; a spacecraft application; a buildingapplication; a construction application; a cartography application; amanufacturing application; a use in combination with at least onetime-of-flight detector. Additionally or alternatively, applications inlocal and/or global positioning systems may be named, especiallylandmark-based positioning and/or indoor and/or outdoor navigation,specifically for use in cars or other vehicles (such as trains,motorcycles, bicycles, trucks for cargo transportation), robots or foruse by pedestrians. Further, indoor positioning systems may be named aspotential applications, such as for household applications and/or forrobots used in manufacturing technology.

Further, the detector according to the present invention may be used inautomatic door openers, such as in so-called smart sliding doors, suchas a smart sliding door disclosed in Jie-Ci Yang et al., Sensors 2013,13(5), 5923-5936; doi:10.3390/s130505923. At least one detectoraccording to the present invention may be used for detecting when aperson or an object approaches the door, and the door may automaticallyopen.

Further applications, as outlined above, may be global positioningsystems, local positioning systems, indoor navigation systems or thelike. Thus, the devices according to the present invention, i.e. one ormore of the detector, the human-machine interface, the entertainmentdevice, the tracking system or the camera, specifically may be part of alocal or global positioning system. Additionally or alternatively, thedevices may be part of a visible light communication system. Other usesare feasible.

The devices according to the present invention, i.e. one or more of thedetector, the human-machine interface, the entertainment device, thetracking system or the camera, further specifically may be used incombination with a local or global positioning system, such as forindoor or outdoor navigation. As an example, one or more devicesaccording to the present invention may be combined withsoftware/database-combinations such as Google Maps® or Google StreetView®. Devices according to the present invention may further be used toanalyze the distance to objects in the surrounding, the position ofwhich can be found in the database. From the distance to the position ofthe known object, the local or global position of the user may becalculated.

Thus, as for the optical detectors and devices disclosed in WO2012/110924 A1 or in U.S. provisional applications 61/739,173, filed onDec. 19, 2012, 61/749,964, filed on Jan. 8, 2013, and 61/867,169, filedon Aug. 19, 2013, and international patent applicationPCT/IB2013/061095, filed on Dec. 18, 2013, the detector, the detectorsystem, the human-machine interface, the entertainment device, thetracking system or the camera according to the present invention (in thefollowing simply referred to as “the devices according to the presentinvention”) may be used for a plurality of application purposes, such asone or more of the purposes disclosed in further detail in thefollowing.

Thus, firstly, the devices according to the present invention may beused in mobile phones, tablet computers, wearable computers, laptops,smart panels or other stationary or mobile computer or communicationapplications. Thus, the devices according to the present invention maybe combined with at least one active light source, such as a lightsource emitting light in the visible range or infrared spectral range,in order to enhance performance. Thus, as an example, the devicesaccording to the present invention may be used as cameras and/orsensors, such as in combination with mobile software for scanningenvironment, objects and living beings. The devices according to thepresent invention may even be combined with 2D cameras, such asconventional cameras, in order to increase imaging effects. The devicesaccording to the present invention may further be used for surveillanceand/or for recording purposes or as input devices to control mobiledevices, especially in combination with voice and/or gesture recognitionand/or eye tracking. Thus, specifically, the devices according to thepresent invention acting as human-machine interfaces, also referred toas input devices, may be used in mobile applications, such as forcontrolling other electronic devices or components via the mobiledevice, such as the mobile phone. As an example, the mobile applicationincluding at least one device according to the present invention may beused for controlling a television set, a game console, a music player ormusic device or other entertainment devices. Further, the devicesaccording to the present invention may be used in webcams or otherperipheral devices for computing applications. Thus, as an example, thedevices according to the present invention may be used in combinationwith software for imaging, recording, surveillance, scanning or motiondetection. As outlined in the context of the human-machine interfaceand/or the entertainment device, the devices according to the presentinvention are particularly useful for giving commands by facialexpressions and/or body expressions. The devices according to thepresent invention can be combined with other input generating deviceslike e.g. a mouse, a keyboard, a touchpad, microphone, an eye trackeretc. Further, the devices according to the present invention may be usedin applications for gaming, such as by using a webcam. Further, thedevices according to the present invention may be used in virtualtraining applications and/or video conferences

Further, the devices according to the present invention may be used inmobile audio devices, television devices and gaming devices, aspartially explained above. Specifically, the devices according to thepresent invention may be used as controls or control devices forelectronic devices, entertainment devices or the like. Further, thedevices according to the present invention may be used for eye detectionor eye tracking, such as in 2D- and 3D-display techniques, especiallywith transparent displays for virtual and/or augmented realityapplications and/or for recognizing whether a display is being looked atand/or from which perspective a display is being looked at.

Further, the devices according to the present invention may be used inor as digital cameras such as DSC cameras and/or in or as reflex camerassuch as SLR cameras. For these applications, reference may be made tothe use of the devices according to the present invention in mobileapplications such as mobile phones and/or smart phones, as disclosedabove.

Further, the devices according to the present invention may be used forsecurity or surveillance applications. Thus, as an example, at least onedevice according to the present invention can be combined with one ormore digital and/or analog electronics that will give a signal if anobject is within or outside a predetermined area (e.g. for surveillanceapplications in banks or museums). Specifically, the devices accordingto the present invention may be used for optical encryption. Detectionby using at least one device according to the present invention can becombined with other detection devices to complement wavelengths, such aswith IR, x-ray, UV-VIS, radar or ultrasound detectors. The devicesaccording to the present invention may further be combined with at leastone active infrared light source and/or at least one active structuredlight source to allow detection in low-light surroundings.

Further, given the ease and accuracy of 3D detection by using thedevices according to the present invention, the devices according to thepresent invention generally may be used for facial, body and personrecognition and identification. Therein, the devices according to thepresent invention may be combined with other detection means foridentification or personalization purposes such as passwords, fingerprints, iris detection, voice recognition or other means. Thus,generally, the devices according to the present invention may be used insecurity devices and other personalized applications.

Further, the devices according to the present invention may be used as3D barcode readers for product identification.

In addition to the security and surveillance applications mentionedabove, the devices according to the present invention generally can beused for surveillance and monitoring of spaces and areas. Thus, thedevices according to the present invention may be used for surveying andmonitoring spaces and areas and, as an example, for triggering orexecuting alarms in case prohibited areas are violated. Thus, generally,the devices according to the present invention may be used forsurveillance purposes in building surveillance or museums, optionally incombination with other types of sensors, such as in combination withmotion or heat sensors, in combination with image intensifiers or imageenhancement devices and/or photomultipliers.

Further, the devices according to the present invention mayadvantageously be applied in camera applications such as video andcamcorder applications. Thus, the devices according to the presentinvention may be used for motion capture and 3D-movie recording.Therein, the devices according to the present invention generallyprovide a large number of advantages over conventional optical devices.Thus, the devices according to the present invention generally require alower complexity with regard to optical components. Thus, as an example,the number of lenses may be reduced as compared to conventional opticaldevices, such as by providing the devices according to the presentinvention having one lens only. Due to the reduced complexity, verycompact devices are possible, such as for mobile use. Conventionaloptical systems having two or more lenses with high quality generallyare voluminous, such as due to the general need for voluminousbeam-splitters. As a further advantage in potential applications ofdevices according to the present invention for motion capturing, thesimplified combination of several cameras in order to cover a scene maybe named, since absolute 3D information may be obtained. This also maysimplify merging scenes recorded by two or more 3D-cameras. Further, thedevices according to the present invention generally may be used forfocus/autofocus devices, such as autofocus cameras. Further, the devicesaccording to the present invention may also be used in opticalmicroscopy, especially in confocal microscopy.

Further, the devices according to the present invention generally areapplicable in the technical field of automotive technology and transporttechnology. Thus, as an example, the devices according to the presentinvention may be used as distance and surveillance sensors, such as foradaptive cruise control, emergency brake assist, lane departure warning,surround view, blind spot detection, rear cross traffic alert, and otherautomotive and traffic applications. Further, the devices according tothe present invention can also be used for velocity and/or accelerationmeasurements, such as by analyzing a first and second time-derivative ofposition information gained by using the detector according to thepresent invention. This feature generally may be applicable inautomotive technology, transportation technology or general traffictechnology. Applications in other fields of technology are feasible. Aspecific application in an indoor positioning system may be thedetection of positioning of passengers in transportation, morespecifically to electronically control the use of safety systems such asairbags. The use of an airbag may be prevented in case the passenger islocated as such, that the use of an airbag will cause a severe injury.Applications in other fields of technology are feasible. For use inautomotive systems, devices according to the present invention may beconnected to one or more electronic control units of the vehicle and mayenable further connections via controller area networks and the like.For testing purposes in automotive or other complex applications,especially for use in combination with further sensors and/or actuators,the integration in hardware-in-the-loop simulation systems is possible.

In these or other applications, generally, the devices according to thepresent invention may be used as stand-alone devices or in combinationwith other sensor devices, such as in combination with radar and/orultrasonic devices. Specifically, the devices according to the presentinvention may be used for autonomous driving and safety issues. Further,in these applications, the devices according to the present inventionmay be used in combination with infrared sensors, radar sensors, whichare sonic sensors, two-dimensional cameras or other types of sensors.The devices according to the present invention specifically may be usedin combination with recognition software, such as standard imagerecognition software. Thus, signals and data as provided by the devicesaccording to the present invention typically are readily processableand, therefore, generally require lower calculation power thanestablished stereovision systems such as LIDAR. Given the low spacedemand, the devices according to the present invention such as camerasmay be placed at virtually any place in a vehicle, such as on a windowscreen, on a front hood, on bumpers, on lights, on mirrors or otherplaces the like. Various detectors according to the present inventionsuch as one or more detectors based on the effect disclosed within thepresent invention can be combined, such as in order to allowautonomously driving vehicles or in order to increase the performance ofactive safety concepts. Thus, various devices according to the presentinvention may be combined with one or more other devices according tothe present invention and/or conventional sensors, such as in thewindows like rear window, side window or front window, on the bumpers oron the lights.

A combination of at least one device according to the present inventionsuch as at least one detector according to the present invention withone or more rain detection sensors is also possible. This is due to thefact that the devices according to the present invention generally areadvantageous over conventional sensor techniques such as radar,specifically during heavy rain. A combination of at least one deviceaccording to the present invention with at least one conventionalsensing technique such as radar may allow for a software to pick theright combination of signals according to the weather conditions.

Further, the devices according to the present invention generally may beused as break assist and/or parking assist and/or for speedmeasurements. Speed measurements can be integrated in the vehicle or maybe used outside the vehicle, such as in order to measure the speed ofother cars in traffic control. Further, the devices according to thepresent invention may be used for detecting free parking spaces inparking lots.

Further, the devices according to the present invention may be used inthe fields of medical systems and sports. Thus, in the field of medicaltechnology, surgery robotics, e.g. for use in endoscopes, may be named,since, as outlined above, the devices according to the present inventionmay require a low volume only and may be integrated into other devices.Specifically, the devices according to the present invention having onelens, at most, may be used for capturing 3D information in medicaldevices such as in endoscopes. Further, the devices according to thepresent invention may be combined with an appropriate monitoringsoftware, in order to enable tracking and analysis of movements. Theseapplications are specifically valuable e.g. in medical treatments andlong-distance diagnosis and tele-medicine. Further, applications forpositioning the body of patients in tomography or radiotherapy arepossible, or for measuring the body shape of patients before surgery, todetect diseases, or the like.

Further, the devices according to the present invention may be appliedin the field of sports and exercising, such as for training, remoteinstructions or competition purposes. Specifically, the devicesaccording to the present invention may be applied in the fields ofdancing, aerobic, football, soccer, basketball, baseball, cricket,hockey, track and field, swimming, polo, handball, volleyball, rugby,sumo, judo, fencing, boxing etc. The devices according to the presentinvention can be used to detect the position of a ball, a bat, a sword,motions, etc., both in sports and in games, such as to monitor the game,support the referee or for judgment, specifically automatic judgment, ofspecific situations in sports, such as for judging whether a point or agoal actually was made.

The devices according to the present invention further may be used inrehabilitation and physiotherapy, in order to encourage training and/orin order to survey and correct movements. Therein, the devices accordingto the present invention may also be applied for distance diagnostics.

Further, the devices according to the present invention may be appliedin the field of machine vision. Thus, one or more of the devicesaccording to the present invention may be used e.g. as a controllingunit for autonomous driving and or working of robots. In combinationwith moving robots, the devices according to the present invention mayallow for autonomous movement and/or autonomous detection of failures inparts. The devices according to the present invention may also be usedfor manufacturing and safety surveillance, such as in order to avoidaccidents including but not limited to collisions between robots,production parts and living beings. In robotics, the safe and directinteraction of humans and robots is often an issue, as robots mayseverely injure humans when they are not recognized. Devices accordingto the present invention may help robots to position objects and humansbetter and faster and allow a safe interaction. One particular advantageof the devices according to the present invention is the low likelihoodof signal interference. Therefore, multiple sensors can work at the sametime in the same environment, without the risk of signal interference.Thus, the devices according to the present invention generally may beuseful in highly automated production environments like e.g. but notlimited to automotive, mining, steel, etc. The devices according to thepresent invention can also be used for quality control in production,e.g. in combination with other sensors like 2-D imaging, radar,ultrasound, IR etc., such as for quality control or other purposes.Further, the devices according to the present invention may be used forassessment of surface quality, such as for surveying the surfaceevenness of a product or the adherence to specified dimensions, from therange of micrometers to the range of meters. Other quality controlapplications are feasible. In a manufacturing environment, the devicesaccording to the present invention are especially useful for processingnatural products such as food or wood, with a complex 3-dimensionalstructure to avoid large amounts of waste material. Further, devicesaccording to the present invention may be used for monitoring thefilling level of tanks, silos etc.

Further, the devices according to the present invention may be used inthe polls, airplanes, ships, spacecraft and other traffic applications.Thus, besides the applications mentioned above in the context of trafficapplications, tracking systems for aircraft, vehicles and the like maybe named. The use of at least one device according to the presentinvention, such as at least one detector according to the presentinvention, for monitoring the speed and/or the direction of movingobjects is feasible. Specifically, the tracking of fast moving objectson land, sea and in the air including space may be named. The at leastone device according to the present invention, such as the at least onedetector according to the present invention, specifically may be mountedon a still-standing and/or on a moving device. An output signal of theat least one device according to the present invention can be combinede.g. with a guiding mechanism for autonomous or guided movement ofanother object. Thus, applications for avoiding collisions or forenabling collisions between the tracked and the steered object arefeasible. The devices according to the present invention generally areuseful and advantageous due to the low calculation power required anddue to the instant response of the detection system. The devicesaccording to the present invention are particularly useful but notlimited to e.g. speed control and air traffic control devices.

The devices according to the present invention generally may be used invarious applications, including guidance for ships in harbors or indangerous areas, and for aircraft at landing or starting. Therein,fixed, known active and/or passive targets may be used for preciseguidance. The same can be used for vehicles driving in dangerous butwell defined routes, such as mining vehicles.

Further, as outlined above, the devices according to the presentinvention may be used in the field of gaming. Thus, the devicesaccording to the present invention can be used with multiple objects ofthe same or of different size, color, shape, etc., such as for movementdetection in combination with software that incorporates the movementinto its content. In particular, applications are feasible inimplementing movements into graphical output. Further, applications ofthe devices according to the present invention for giving commands arefeasible, such as by using one or more of the devices according to thepresent invention for gesture or facial recognition. The devicesaccording to the present invention may be combined with an active systemin order to work under e.g. low-light conditions or in other situationsin which enhancement of the surrounding conditions is required.Additionally or alternatively, a combination of one or more of thedevices according to the present invention with one or more IR or VISlight sources is possible. A combination of a detector according to thepresent invention with special devices is also possible, which can bedistinguished easily by the system and its software, e.g. and notlimited to, a special color, shape, relative position to other devices,speed of movement, light, frequency used to modulate light sources onthe device, surface properties, material used, reflection properties,transparency degree, absorption characteristics, etc. The device can,amongst other possibilities, resemble a stick, a racquet, a club, a gun,a knife, a wheel, a ring, a steering wheel, a bottle, a ball, a glass, avase, a spoon, a fork, a cube, a dice, a figure, a puppet, a teddy, abeaker, a pedal, a hat, a pair of glasses, a helmet, a switch, a glove,jewelry, a musical instrument or an auxiliary device for playing amusical instrument, such as a plectrum, a drumstick or the like. Otheroptions are feasible.

Further, the devices according to the present invention generally may beused in the field of building, construction and cartography. Thus,generally, one or more devices according to the present invention may beused in order to measure and/or monitor environmental areas, e.g.countryside or buildings. Therein, one or more of the devices accordingto the present invention may be combined with other methods and devicesor can be used solely in order to monitor progress and accuracy ofbuilding projects, changing objects, houses, etc. The devices accordingto the present invention can be used for generating three-dimensionalmodels of scanned environments, in order to construct maps of rooms,streets, houses, communities or landscapes, both from ground or fromair. Potential fields of application may be construction, cartography,real estate management, land surveying or the like.

One or more devices according to the present invention can further beused for scanning of objects, such as in combination with CAD or similarsoftware, such as for additive manufacturing and/or 3D printing.Therein, use may be made of the high dimensional accuracy of the devicesaccording to the present invention, e.g. in x-, y- or z-direction or inany arbitrary combination of these directions, such as simultaneously.Further, the devices according to the present invention may be used ininspections and maintenance, such as pipeline inspection gauges.

As outlined above, the devices according to the present invention mayfurther be used in manufacturing, quality control or identificationapplications, such as in product identification or size identification(such as for finding an optimal place or package, for reducing wasteetc.). Further, the devices according to the present invention may beused in logistics applications. Thus, the devices according to thepresent invention may be used for optimized loading or packingcontainers or vehicles. Further, the devices according to the presentinvention may be used for monitoring or controlling of surface damagesin the field of manufacturing, for monitoring or controlling rentalobjects such as rental vehicles, and/or for insurance applications, suchas for assessment of damages. Further, the devices according to thepresent invention may be used for identifying a size of material, objector tools, such as for optimal material handling, especially incombination with robots and/or for ensuring quality or accuracy in amanufacturing process, such as the accuracy of product size or volume orthe optical precision of a manufactured lens. Further, the devicesaccording to the present invention may be used for process control inproduction, e.g. for observing filling level of tanks. Further, thedevices according to the present invention may be used for maintenanceof production assets like, but not limited to, tanks, pipes, reactors,tools etc. Further, the devices according to the present invention maybe used for analyzing 3D-quality marks. Further, the devices accordingto the present invention may be used in manufacturing tailor-made goodssuch as tooth inlays, dental braces, prosthesis, clothes or the like.The devices according to the present invention may also be combined withone or more 3D-printers for rapid prototyping, 3D-copying or the like.Further, the devices according to the present invention may be used fordetecting the shape of one or more articles, such as for anti-productpiracy and for anti-counterfeiting purposes.

The detector according to the present invention, comprising the at leastone longitudinal optical sensor, the at least one illumination sourceand the at least one evaluation device, may further be combined with oneor more other types of sensors or detectors. In the following, thedetector comprising the at least one longitudinal optical sensor havinga sensor signal being dependent on a photon density of the light beamwill also be referred to as the FiP detector. Thus, the FiP detector mayfurther comprise at least one additional detector. The at least oneadditional detector may be adapted for detecting at least one parameter,such as at least one of: a parameter of a surrounding environment, suchas a temperature and/or a brightness of a surrounding environment; aparameter regarding a position and/or orientation of the detector; aparameter specifying a state of the object to be detected, such as aposition of the object, e.g. an absolute position of the object and/oran orientation of the object in space. Thus, generally, the principlesof the present invention may be combined with other measurementprinciples in order to gain additional information and/or in order toverify measurement results or reduce measurement errors or noise.

Specifically, the FiP detector according to the present invention mayfurther comprise at least one time-of-flight (ToF) detector adapted fordetecting at least one distance between the at least one object and thedetector by performing at least one time-of-flight measurement. As usedherein, a time-of-flight measurement generally refers to a measurementbased on a time a signal needs for propagating between two objects orfrom one object to a second object and back. In the present case, thesignal specifically may be one or more of an acoustic signal or anelectromagnetic signal such as a light signal. A time-of-flight detectorconsequently refers to a detector adapted for performing atime-of-flight measurement. Time-of-flight measurements are well-knownin various fields of technology such as in commercially availabledistance measurement devices or in commercially available flow meters,such as ultrasonic flow meters. Time-of-flight detectors even may beembodied as time-of-flight cameras. These types of cameras arecommercially available as range-imaging camera systems, capable ofresolving distances between objects based on the known speed of light.

Presently available ToF detectors generally are based on the use of apulsed signal, optionally in combination with one or more light sensorssuch as CMOS-sensors. A sensor signal produced by the light sensor maybe integrated. The integration may start at two different points intime. The distance may be calculated from the relative signal intensitybetween the two integration results.

Further, as outlined above, ToF cameras are known and may generally beused, also in the context of the present invention. These ToF camerasmay contain pixelated light sensors. However, since each pixel generallyhas to allow for performing two integrations, the pixel constructiongenerally is more complex and the resolution of commercially availableToF cameras is rather low (typically 200×200 pixels). Distances below˜40 cm and above several meters typically are difficult or impossible todetect. Furthermore, the periodicity of the pulses leads to ambiguousdistances, as only the relative shift of the pulses within one period ismeasured.

ToF detectors, as standalone devices, typically suffer from a variety ofshortcomings and technical challenges. Thus, in general, ToF detectorsand, more specifically, ToF cameras suffer from rain and othertransparent objects in the light path, since the pulses might bereflected too early, objects behind the raindrop are hidden, or inpartial reflections the integration will lead to erroneous results.Further, in order to avoid errors in the measurements and in order toallow for a clear distinction of the pulses, low-light conditions arepreferred for ToF-measurements. Bright light such as bright sunlight canmake a ToF-measurement impossible. Further, the energy consumption oftypical ToF cameras is rather high, since pulses must be bright enoughto be back-reflected and still be detectable by the camera. Thebrightness of the pulses, however, may be harmful for eyes or othersensors or may cause measurement errors when two or more ToFmeasurements interfere with each other. In summary, current ToFdetectors and, specifically, current ToF cameras suffer from severaldisadvantages such as low resolution, ambiguities in the distancemeasurement, limited range of use, limited light conditions, sensitivitytowards transparent objects in the light path, sensitivity towardsweather conditions and high energy consumption. These technicalchallenges generally lower the aptitude of present ToF cameras for dailyapplications such as for safety applications in cars, cameras for dailyuse or human-machine-interfaces, specifically for use in gamingapplications.

In combination with the FiP detector, the advantages and capabilities ofboth systems may be combined in a fruitful way. Thus, the FiP detectormay provide advantages at bright light conditions, while the ToFdetector generally provides better results at low-light conditions. Acombined device, i.e. a detector including the FiP detector and furtherincluding at least one ToF detector, therefore provides increasedtolerance with regard to light conditions as compared to both singlesystems. This is especially important for safety applications, such asin cars or other vehicles.

Specifically, the detector may be designed to use at least one ToFmeasurement for correcting at least one measurement performed by usingthe FiP detector and vice versa. Further, the ambiguity of a ToFmeasurement may be resolved by using the FiP detector. A measurementusing the FiP detector specifically may be performed whenever ananalysis of ToF measurements results in a likelihood of ambiguity.Additionally or alternatively, measurements using the FiP detector maybe performed continuously in order to extend the working range of theToF detector into regions which are usually excluded due to theambiguity of ToF measurements. Additionally or alternatively, the FiPdetector may cover a broader or an additional range to allow for abroader distance measurement region. The FiP detector may further beused for determining one or more important regions for measurements toreduce energy consumption or to protect eyes. Thus, the FiP detector maybe adapted for detecting one or more regions of interest. Additionallyor alternatively, the FiP detector may be used for determining a roughdepth map of one or more objects within a scene captured by thedetector, wherein the rough depth map may be refined in importantregions by one or more ToF measurements. Further, the FiP detector maybe used to adjust the ToF detector, such as the ToF camera, to therequired distance region. Thereby, a pulse length and/or a frequency ofthe ToF measurements may be pre-set, such as for removing or reducingthe likelihood of ambiguities in the ToF measurements. Thus, generally,the FiP detector may be used for providing an autofocus for the ToFdetector, such as for the ToF camera.

As outlined above, a rough depth map may be recorded by the FiPdetector. Further, the rough depth map, containing depth information orz-information regarding one or more objects within a scene captured bythe detector, may be refined by using one or more ToF measurements. TheToF measurements specifically may be performed only in importantregions. Additionally or alternatively, the rough depth map may be usedto adjust the ToF detector, specifically the ToF camera.

Further, the use of the FiP detector in combination with the at leastone ToF detector may solve the above-mentioned problem of thesensitivity of ToF detectors towards the nature of the object to bedetected or towards obstacles or media within the light path between thedetector and the object to be detected, such as the sensitivity towardsrain or weather conditions. A combined measurement may be used toextract the important information from ToF signals, or measure complexobjects with several transparent or semi-transparent layers. Thus,objects made of glass, crystals, liquid structures, phase transitions,liquid motions, etc. may be observed. Further, the combination of a FiPdetector and at least one ToF detector will still work in rainy weather,and the overall detector will generally be less dependent on weatherconditions. As an example, measurement results provided by the FiPdetector may be used to remove the errors provoked by rain from ToFmeasurement results, which specifically renders this combination usefulfor safety applications such as in cars or other vehicles.

The implementation of at least one ToF detector into the detectoraccording to the present invention may be realized in various ways.Thus, the at least one FiP detector and the at least one ToF detectormay be arranged in a sequence, within the same light path. As anexample, at least one transparent longitudinal optical sensor may beplaced in front of at least one ToF detector. Additionally oralternatively, separate light paths or split light paths for the FiPdetector and the ToF detector may be used. Therein, as an example, lightpaths may be separated by one or more beam-splitting elements, such asone or more of the beam splitting elements listed above or listed infurther detail below. As an example, a separation of beam paths bywavelength-selective elements may be performed. Thus, e.g., the ToFdetector may make use of infrared light, whereas the FiP detector maymake use of light of a different wavelength. In this example, theinfrared light for the ToF detector may be separated off by using awavelength-selective beam splitting element such as a hot mirror.Additionally or alternatively, light beams used for the measurementusing the FiP detector and light beams used for the ToF measurement maybe separated by one or more beam-splitting elements, such as one or moresemitransparent mirrors, beam-splitter cubes, polarization beamsplitters or combinations thereof. Further, the at least one FiPdetector and the at least one ToF detector may be placed next to eachother in the same device, using distinct optical pathways. Various othersetups are feasible.

The at least one optional ToF detector may be combined with basicallyany of the embodiments of the detector according to the presentinvention. Specifically, the at least one ToF detector which may be asingle ToF detector or a ToF camera, may be combined with a singleoptical sensor or with a plurality of optical sensors such as a sensorstack. Further, the detector may also comprise one or more imagingdevices such as one or more inorganic imaging devices like CCD chipsand/or CMOS chips, preferably one or more full-color CCD chips orfull-color CMOS chips. Additionally or alternatively, the detector mayfurther comprise one or more thermographic cameras.

As outlined above, the detector according to the present invention aswell as one or more of the other devices as proposed within the presentinvention may be combined with one or more other types of measurementdevices. Thus, the detector according to the present invention may becombined with one or more other types of sensors or detectors, such asthe above-mentioned ToF detector. When combining the optical detectoraccording to the present invention with one or more other types ofsensors or detectors, the at least one detector of the present inventionand the at least one further sensor or detector may be designed asindependent devices, with the at least one detector being separate fromthe at least one further sensor or detector. Alternatively, the detectorand the further sensor or detector may fully or partially be integratedor designed as a single device.

Thus, as a non-limiting example, the detector may further comprise astereo camera. As used herein, a stereo camera is a camera which isdesigned for capturing images of a scene or an object from at least twodifferent perspectives. Thus, the detector may comprise the at least onelongitudinal optical sensor, the at least one illumination source andthe at least one evaluation device, which, in combination, may form anactive distance sensor, with the potential embodiments and optionalcomponents and functionality as disclosed above, and, further, at leastone stereo camera. Consequently, the detector according to the presentinvention may comprise at least one active distance sensor and at leastone stereo camera.

The stereo camera's functionality is generally known in the art, sincestereo cameras generally are known to the skilled person. Thecombination with the active distance sensor according to the presentinvention may provide additional distance information. Thus, thedetector may be adapted, in addition to the stereo camera's information,to provide at least one item of information on a longitudinal positionof at least one object within a scene captured by the stereo camera.Information provided by the stereo camera, such as distance informationobtained by evaluating triangulation measurements performed by using thestereo camera, may be calibrated and/or validated by using the activedistance sensor. Thus, as an example, the stereo camera may be used toprovide at least one first item of information on the longitudinalposition of the at least one object, such as by using triangulationmeasurements, and the active distance sensor may be used to provide atleast one second item of information on the longitudinal position of theat least one object. The first item of information and the second itemof information may be used to improve accuracy of the measurements.Thus, the first item of information may be used for calibrating thesecond item of information or vice a versa. Consequently, the detector,as an example, may form a stereo camera system, having the stereo cameraand the active distance sensor, wherein the stereo camera system isadapted to calibrate the information provided by the stereo camera byusing the information provided by the active distance sensor.

Consequently, additionally or alternatively, the detector may be adaptedto use the second item of information, provided by the active distancesensor, for correcting the first item of information, provided by thestereo camera. Additionally or alternatively, the detector may beadapted to use the second item of information, provided by the activedistance sensor, for correcting optical distortion of the stereo camera.Further, the detector may adapted to calculate stereo informationprovided by the stereo camera, and the second item of informationprovided by the active distance sensor may be used for speeding up thecalculation of the stereo information.

As an example, the detector may be adapted to use at least one virtualor real object within a scene captured by the detector for calibratingthe stereo camera. As an example, one or more objects and/or areasand/or spots may be used for calibration. As an example, the distance ofat least one object or spot may be determined by using the activedistance sensor, and distance information provided by the stereo cameramay be calibrated by using this distance is determined by using theactive distance sensor. For instance, at least one active light spot ofthe active distance sensor may be used as a calibration point for thestereo camera. The active light spot, as an example, may move freely inthe picture.

The detector may be adapted to continuously or discontinuously calibratethe stereo camera by using information provided by the active distancesensor. Thus, as an example, the calibration may take place at regularintervals, continuously or occasionally.

Further, typical stereo cameras exhibit measurement errors oruncertainties which are dependent on the distance of the object. Thismeasurement error may be reduced when combined with information providedby the active distance sensor.

Combinations of stereo cameras with other types of distance sensors aregenerally known in the art. Thus, in D. Scaramuzza et al., IEEE/RSJInternational Conference on Intelligent Robots and Systems, 2007. IROS2007. Pages 4164-4169, an extrinsic self calibration of a camera and a3D laser range finder from natural scenes is disclosed. Similarly, in D.Klimentjew et al., 2010 IEEE Conference on Multisensor Fusion andIntegration for Intelligent Systems (MFI), pages 236-241, a multi sensorfusion of camera and 3D laser range finder for object recognition isdisclosed. As the skilled person will recognize, the laser range finderin these setups known in the art may simply be replaced or complementedby at least one active distance sensor according to the presentinvention, without altering the methods and advantages disclosed bythese prior art documents. For potential setups of the stereo camera,reference may be made to these prior art documents. Still, other setupsand embodiments of the at least one optional stereo camera are feasible.

Summarizing the above-mentioned findings, the following embodiments arepreferred within the present invention:

Embodiment 1

A detector for determining a position of at least one object,comprising:

-   -   at least one longitudinal optical sensor, wherein the        longitudinal optical sensor has at least one sensor region,        wherein the longitudinal optical sensor is at least partially        transparent, wherein the longitudinal optical sensor is designed        to generate at least one longitudinal sensor signal in a manner        dependent on an illumination of the sensor region by at least        one light beam traveling from the object to the detector,        wherein the longitudinal sensor signal, given the same total        power of the illumination, is dependent on a beam cross-section        of the light beam in the sensor region    -   at least one illumination source adapted to illuminate the        object with illumination light through the longitudinal optical        sensor; and    -   at least one evaluation device, wherein the evaluation device is        designed to generate at least one item of information on a        longitudinal position of the object by evaluating the        longitudinal sensor signal.

Embodiment 2

The detector according to the preceding embodiment, wherein the detectorfurther comprises at least one reflective element, wherein thereflective element is adapted to reflect the illumination light beforeilluminating the object.

Embodiment 3

The detector according to the preceding embodiment, wherein thereflective element comprises at least one movable reflective elementadapted to be adjusted to at least two different positions, wherein, inthe at least two different positions, the illumination light isreflected into different directions.

Embodiment 4

The detector according to the preceding embodiment, wherein the at leastone movable reflective element is adapted to scan the illumination lightthrough at least one scan region in space.

Embodiment 5

The detector according to any one of the two preceding embodiments,wherein the at least one movable reflective element comprises at leastone movable mirror.

Embodiment 6

The detector according to any one of the three preceding embodiments,wherein the at least one movable reflective element comprises at leastone array of movable mirrors, specifically at least one array ofmicro-mirrors and more specifically a DLP® array.

Embodiment 7

The detector according to any one of the five preceding embodiments,wherein the reflective element is adapted to reflect light in theinfrared spectral range, wherein light in the visible spectral range istransmitted.

Embodiment 8

The detector according to any one of the six preceding embodiments,wherein the reflective element is selected from the group consisting of:a mirror; a semitransparent mirror; a mirror or semi-transparent mirrorreflecting only specific spectral regions, such as light in the infraredspectral range; a prism; a dichroitic mirror; a beam splitter cube.

Embodiment 9

The detector according to any one of the preceding embodiments, whereinthe detector further comprises at least one imaging device, wherein theimaging device is adapted such that the light beam traveling from theobject to the detector passes through the longitudinal optical sensorbefore impinging on the imaging device.

Embodiment 10

The detector according to the preceding embodiment, wherein the imagingdevice comprises a camera chip.

Embodiment 11

The detector according to any one of the two preceding embodiments,wherein the imaging device comprises an inorganic imaging device.

Embodiment 12

The detector according to any one of the three preceding embodiments,wherein the imaging device comprises a matrix of pixels.

Embodiment 13

The detector according to any one of the four preceding embodiments,wherein the imaging device comprises a chip selected from the groupconsisting of a CMOS chip and a CCD chip.

Embodiment 14

The detector according to any one of the five preceding embodiments,wherein the imaging device is adapted to resolve colors.

Embodiment 15

The detector according to the preceding embodiment, wherein the imagingdevice is a full-color CCD or CMOS chip.

Embodiment 16

The detector according to any one of the seven preceding embodiments,wherein the detector further comprises at least one beam-splittingdevice, wherein the beam splitting device is adapted to separate theillumination light emitted by the illumination source before passing thelongitudinal optical sensor from the light beam traveling from theobject to the detector after passing the longitudinal optical sensor.

Embodiment 17

The detector according to the preceding embodiment, wherein the beamsplitting device is selected from the group consisting of: asemitransparent mirror; a mirror or semi-transparent mirror reflectingonly specific spectral regions, such as light in the infrared spectralrange; a prism; a dichroitic mirror; a beam splitter cube.

Embodiment 18

The detector according to any one of the two preceding embodiments,wherein the beam-splitting device is a movable reflective elementadapted to be adjusted to at least two different positions, wherein, inthe at least two different positions, the illumination light isreflected into different directions.

Embodiment 19

The detector according to any one of the preceding embodiments, whereinthe longitudinal sensor signal is further dependent on a modulationfrequency of the light beam.

Embodiment 20

The detector according to any one of the preceding embodiments, whereinthe illumination source is adapted to periodically modulate at least oneoptical property of the illumination light.

Embodiment 21

The detector according to the preceding embodiment, wherein the at leastone optical property is selected from the group consisting of anamplitude and a phase of the illumination light.

Embodiment 22

The detector according to any one of the preceding embodiments, whereinthe detector comprises at least one optical device, wherein the opticaldevice comprises at least one element having one or both of a focusingor a defocusing effect onto at least one of the illumination light andthe light beam.

Embodiment 23

The detector according to the preceding embodiment, wherein the at leastone optical device fully or partially is positioned in one or more ofthe following positions

-   -   in a beam path in between the illumination source and the        longitudinal optical sensor;    -   in a beam path between the longitudinal optical sensor and the        object;    -   in a beam path in between the longitudinal optical sensor and an        imaging device adapted such that the light beam traveling from        the object to the detector passes through the longitudinal        optical sensor before passing the optical device and impinging        on the imaging device.

Embodiment 24

The detector according to any one of the two preceding embodiments,wherein the optical device comprises at least one element selected fromthe group consisting of: a focusing lens; a defocusing lens; a cameralens; a curved mirror; a diaphragm.

Embodiment 25

The detector according to any one of the preceding embodiments, whereinthe at least one longitudinal optical sensor comprises a sensor stack ofat least two longitudinal optical sensors.

Embodiment 26

The detector according to the preceding embodiment, wherein the sensorstack is composed of the longitudinal optical sensors being arrangedsuch that the sensor regions of the longitudinal optical sensors areoriented essentially perpendicular to an optical axis of the detector.

Embodiment 27

The detector according to any one of the preceding embodiments, whereinthe illumination light has a wavelength in the infrared spectral range.

Embodiment 28

The detector according to any one of the preceding embodiments, whereinthe illumination light at least partially travels substantially parallelto an optical axis of the detector.

Embodiment 29

The detector according to any one of the preceding embodiments, whereinthe longitudinal optical sensor, the illumination source and,optionally, the imaging device are arranged coaxially with regard to anoptical axis of the detector.

Embodiment 30

The detector according to any of the preceding embodiments, wherein thelongitudinal optical sensor comprises at least one semiconductordetector.

Embodiment 31

The detector according to the preceding embodiment, wherein thesemiconductor detector is an organic semiconductor detector comprisingat least one organic material.

Embodiment 32

The detector according to any one of the two preceding embodiments,wherein the semiconductor detector is selected from the group consistingof an organic solar cell, a dye solar cell, a dye-sensitized solar cell,a solid dye solar cell, a solid dye-sensitized solar cell.

Embodiment 33

The detector according to any one of the preceding embodiments, whereinthe longitudinal optical sensor comprises at least one first electrode,at least one n-semiconducting metal oxide, at least one dye, at leastone p-semiconducting organic material, preferably a solidp-semiconducting organic material, and at least one second electrode.

Embodiment 34

The detector according to the preceding embodiment, wherein both thefirst electrode and the second electrode are transparent.

Embodiment 35

The detector according to any one of the preceding embodiments, whereinthe evaluation device is designed to generate the at least one item ofinformation on the longitudinal position of the object from at least onepredefined relationship between a geometry of the illumination of thesensor region by the light beam and a relative positioning of the objectwith respect to the detector.

Embodiment 36

The detector according to the preceding embodiment, wherein thepredefined relationship between the geometry of the illumination of thesensor region by the light beam and the relative positioning of theobject with respect to the detector is taking account of a known powerof the illumination.

Embodiment 37

The detector according to any one of the two preceding embodiments,wherein the predefined relationship between the geometry of theillumination of the sensor region by the light beam and the relativepositioning of the object with respect to the detector is taking accountof a modulation frequency with which the illumination light ismodulated.

Embodiment 38

The detector according to any one of the three preceding embodiment,wherein the illumination source is adapted to send out at least twolight beams having differing optical properties.

Embodiment 39

The detector according to the preceding embodiment, wherein the at leasttwo light beams have a differing spectral properties.

Embodiment 40

The detector according to any one of the two preceding embodiments,wherein the at least two light beams are modulated with differentmodulation frequencies.

Embodiment 41

The detector according to any one of the preceding embodiments, whereinthe detector further comprises at least one time-of-flight detectoradapted for detecting at least one distance between the at least oneobject and the detector by performing at least one time-of-flightmeasurement.

Embodiment 42

The detector according to any one of the preceding embodiments, whereinthe detector further comprises at least one stereo camera.

Embodiment 43

A human-machine interface for exchanging at least one item ofinformation between a user and a machine, wherein the human-machineinterface comprises at least one detector according to any one of thepreceding embodiments, wherein the human-machine interface is designedto generate at least one item of geometrical information of the user bymeans of the detector, wherein the human-machine interface is designedto assign to the geometrical information at least one item ofinformation, in particular at least one control command.

Embodiment 44

The human-machine interface according to the preceding embodiment,wherein the generation of the item of information is effected by a bodyposture and/or a movement of a user.

Embodiment 45

An entertainment device for carrying out at least one entertainmentfunction, wherein the entertainment device comprises at least onehuman-machine interface according to the two preceding embodiments,wherein the entertainment device is designed to enable at least one itemof information to be input by a player by means of the human-machineinterface, wherein the entertainment device is designed to vary theentertainment function in accordance with the information.

Embodiment 46

A tracking system for tracking the position of at least one movableobject, the tracking system comprising a detector according to any oneof the preceding embodiments relating to a detector, the tracking systemfurther comprising at least one track controller, wherein the trackcontroller is adapted to track a series of positions of the object atspecific points in time.

Embodiment 47

The tracking system according to the preceding embodiment, wherein thetrack controller is adapted to determine from the series of positions amovement of the object.

Embodiment 48

A camera for imaging at least one object, the camera comprising at leastone detector according to any one of the preceding embodiments referringto a detector.

Embodiment 49

A method for determining a position of at least one object, inparticular using a detector according to any one of the precedingembodiments relating to a detector, the method comprising:

-   -   using at least one longitudinal optical sensor of the detector,        wherein the longitudinal optical sensor has at least one sensor        region, wherein the longitudinal optical sensor is at least        partially transparent, wherein the longitudinal optical sensor        generates at least one longitudinal sensor signal in a manner        dependent on an illumination of the sensor region by at least        one light beam traveling from the object to the detector,        wherein the longitudinal sensor signal, given the same total        power of the illumination, is dependent on a beam cross-section        of the light beam in the sensor region;    -   illuminating the object with illumination light through the        longitudinal optical sensor by using at least one illumination        source; and    -   generating at least one item of information on a longitudinal        position of the object by evaluating the longitudinal sensor        signal by using at least one evaluation device.

Embodiment 50

The method according to the preceding embodiment, wherein in thegeneration step, the item of information on the longitudinal position isgenerated by considering an input signal of the illumination source.

Embodiment 51

The method according to the preceding embodiment, wherein the inputsignal of the illumination source is subtracted from the longitudinalsensor signal.

Embodiment 52

A use of the detector according to any one of the preceding embodimentsrelating to a detector, for a purpose of use, selected from the groupconsisting of: a position measurement in traffic technology; anentertainment application; a security application; a human-machineinterface application; a tracking application; a photographyapplication; an imaging application or camera application; a mappingapplication for generating maps of at least one space; a use incombination with at least one time-of-flight measurement; an applicationin a local positioning system; an application in a global positioningsystem; an application in a landmark-based positioning system; anapplication in an indoor navigation system; an application in an outdoornavigation system; an application in a household application; a robotapplication; an application in an automatic door opener; an applicationin a light communication system, specifically in a visible lightcommunication system, i.e. a communication system based on the use ofvisible light; an application in conjunction with a stereo camera.

BRIEF DESCRIPTION OF THE FIGURES

Further optional details and features of the invention are evident fromthe description of preferred exemplary embodiments which follows inconjunction with the dependent claims. In this context, the particularfeatures may be implemented alone or in any reasonable combination. Theinvention is not restricted to the exemplary embodiments. The exemplaryembodiments are shown schematically in the figures. Identical referencenumerals in the individual figures refer to identical elements orelements with identical function, or elements which correspond to oneanother with regard to their functions.

EXEMPLARY EMBODIMENTS

In FIG. 1, the occurrence of a shadow 110 in the determination of aposition of at least one object 112 using an illumination source 114 andan imaging device 116 is depicted. The imaging device 116 may bearranged displaced from an optical axis of the illumination source 114.A light beam emitted by the illumination source 114 may illuminate apoint and/or a region of the object 112. However, the displacement ofthe illumination 114 and the imaging device 116 may cause a shadow 110.The shadow 110 may be a region which in principle can be viewed by theimaging device 116, but which is not illuminated by the illuminationsource 114. In addition, a position of the shadow 110 may depend on therelative arrangement of the illumination source 114 and the imagingdevice 116.

FIG. 2 shows an embodiment of a detector 118 according to the presentinvention, for determining a position of at least one object 112. Thedetector 118 in this embodiment or other embodiments of the presentinvention, may be a stand-alone-detector or may be combined with one ormore other detectors. As an example, the detector 118 may form a camera119 or may be part of a camera 119. Additionally or alternatively, aswill be outlined in further detail below, the detector 118 may be partof a human-machine interface 148, an entertainment device 154 or atracking system 156. Other applications are feasible.

The detector 118 comprises at least one illumination source 114, forexample a laser, in particular an IR laser diode, a light-emittingdiode, an incandescent lamp, an organic light source, in particular anorganic light-emitting diode. The illumination source 114 may emitillumination light 115, which may illuminate the object 112. Theillumination source 114 may be adapted to send out at least two lightbeams having differing optical properties, for example the at least twolight beams may be modulated with different modulation frequencies.

Further, the detector 118 comprises at least one longitudinal opticalsensor 120. The detector 118 may comprise one or more longitudinaloptical sensors 120. The longitudinal optical sensor 120 has at leastone sensor region 124. In this embodiment, the detector 118 may comprisea plurality of longitudinal optical sensors 120, which are arranged in asensor stack 122. The longitudinal optical sensors 120 are at leastpartially transparent. The illumination source 114 is adapted toilluminate the object 112 with illumination light 115 through thelongitudinal optical sensor 120. The illumination light 115 may travelfrom the illumination source 114 through the longitudinal optical sensor120 and may impinge on the object 112. The object 112 may reflect theimpinging light. Thus, at least one light beam 126 may travel from theobject 112 to the detector 118. The longitudinal optical sensor 120 isdesigned to generate at least one longitudinal sensor signal in a mannerdependent on an illumination of the sensor region 124 by at least onelight beam 126 traveling from the object 112 to the detector 118. Atleast one or more of the longitudinal optical sensors 120 may be aFiP-sensor, as discussed above and as discussed in further detail e.g.in WO 2012/110924 A1. Thus, the longitudinal sensor signal, given thesame total power of the illumination, is dependent on a beamcross-section of a light beam 126 and/or the illumination light 115 inthe sensor region 124.

An axis orthogonally to a surface of the longitudinal optical sensor 120may define an optical axis 128. The optical axis 128 defines alongitudinal axis or z-axis, wherein a plane perpendicular to theoptical axis 128 defines an x-y-plane. Thus, in FIG. 2, a coordinatesystem 130 is shown, which may be a coordinate system of the detector118 and in which, fully or partially, at least one item of informationregarding the position of the object 112 may be determined. Theillumination light 115 may propagate in a direction of propagation 132,which is preferably parallel to the z-axis.

The illumination source 114 and the longitudinal sensor 120 may bearranged coaxially with regard to the optical axis 128. Thus, thecomponents selected from the group consisting of the illumination source114 and the longitudinal optical sensor 120 are not displaced from thecommon optical axis 128, such that shadows 110 and/or, as outlinedabove, parallaxes problems do not occur.

The detector 118, in this embodiment, furthermore may comprise one ormore optical devices 134. The optical devices 134 may have a focusing ora defocusing effect onto at least one of the illumination light 115 andthe light beam 126. The optical device 134 may be realized as one ormore of a focusing lens; a defocusing lens; a camera lens; a curvedmirror; a diaphragm. The optical devices 134 may be arranged on thecommon optical axis 128.

Further, the detector 118 comprises an evaluation device 136 designed togenerate at least one item of information on a longitudinal position ofthe object 112 by evaluating the longitudinal sensor signal. Theevaluation device 136 may contain one or more data processing devices138 and/or one or more data memories 140. The evaluation device may beadapted to perform a frequency analysis, in particular a Fourieranalysis, of the longitudinal sensor signal. Thus, in case illuminationsource 114 may send out more than one light beam of illumination light115, each light beam modulated with a different modulation frequency,the evaluation device 136 may be adapted to determine the signalcomponents of the longitudinal sensor signal of each light beam.

The evaluation device 136 may be connected to the longitudinal opticalsensors 120 and the illumination source 114 by one or more connectors142. Further, the connector 142 may comprise one or more drivers and/orone or more measurement devices for generating sensor signals.

The components of the detector 118 may fully or partially be embodied inone or more housings 144. Thus, the longitudinal optical sensor 120, theoptical devices 134 and the illumination source 114 may be encased fullyor partially within the same housing 144 and/or may fully or partiallybe encased within separate housings. Further, the evaluation device 136may fully or partially be integrated into the longitudinal opticalsensors 120 and/or into the housing 144. Additionally or alternatively,the evaluation device 136 may fully or partially be designed as aseparate, independent device.

In FIG. 3, in addition to the explanations given above with regard toFIG. 2, a further embodiment of a detector 118 for determining aposition of at least one object 112 is shown. In this preferredembodiment, the detector 118 may comprise imaging device 116, which maybe arranged on the optical axis 128 defined by the longitudinal opticalsensor 120. The imaging device 116 may be adapted such that the lightbeam 126 traveling from the object 112 to the detector 118 passesthrough the longitudinal optical sensor 120 before impinging on theimaging device 116. The imaging device 116 may comprise a camera chip,which may be selected from the group consisting of a CMOS chip and a CCDchip. Preferably, the imaging device 116 may be adapted to resolvecolors, thus, the imaging device 116 may be a full color CCD chip. Theimaging device 116 may comprise an inorganic imaging device. Further,the imaging device may comprise a matrix of pixels. The imaging device116 may be part of the housing 144. In FIG. 3, the detector 118 maycomprise three optical devices 134, which are adapted to focus ordefocus illumination light 115 and/or the light beam 126.

The illumination source 114 may be displaced from the optical axis 128,because one or more of the imaging device 116 and the illuminationsource 114 may be intransparent to light. To prevent the appearance ofshadows 110 and parallaxes problems, the illumination light 115 may bedeflected to the optical axis 128 by at least one beam-splitting device146. The beam-splitting device 146 may be adapted to separate theillumination light 115 before passing the longitudinal optical sensor120 from the light beam 126 traveling from the object 112 to thedetector 118 after passing the longitudinal optical sensor 120. Thebeam-splitting device 146 may be selected from the group consisting of:a semitransparent mirror; a prism; a dichroitic mirror; a beam splittercube.

In FIG. 4, an exemplary embodiment of the detector 118 used in ahuman-machine interface 148 is shown. The human-machine interface 148comprises at least one detector 118. The human-machine interface may bedesigned to generate at least one item of geometrical information of theuser 115 by means of the detector 118. The human-machine interface 148may be used to assign to the geometrical information at least one itemof information, in particular at least one control command, in order toprovide at least one item of information to a machine 152. In theembodiments schematically depicted in FIG. 4, the machine 152 may be acomputer and/or may comprise a computer. Other embodiments are feasible.The evaluation device 136 may fully or partially be integrated into themachine 152, such as into the computer.

The human-machine interface 148 may form part of an entertainment device154. The machine 152, specifically the computer, may also form part ofthe entertainment device 154. Thus, by means of the user 150 functioningas the object 112, the user 150 may input at least one item ofinformation, such as at least one control command, into the computer,thereby varying an entertainment function, such as controlling thecourse of a computer game.

Further, a tracking system 156 for tracking the position of at least onemovable object 112 is depicted. The tracking system 156 comprises thedetector 118 and, further, at least one track controller 158. The trackcontroller 158 may fully or partially form part of the computer of themachine 152. The track controller 158 is adapted to track a movement ofthe object 112 from a series of positions of the object 112 at specificpoints in time.

In FIG. 5, an alternative embodiment of the setup of the detector 118 ofFIG. 2 is shown. Thus, for most components of the embodiment in FIG. 5,reference may be made to the description of FIG. 2 above. Still, in thisembodiment, the detector 118 further comprises at least one reflectiveelement 160 adapted for reflecting, specifically for deflecting, theillumination light 115 and, thus, to change the direction of propagationof the illumination light 115.

Preferably, the reflective element 160 is a movable reflective element162 which is capable of changing at least one position, preferably atleast on orientation 164, as indicated in FIG. 5. The position of thereflective element 160 may be controllable, such as by the evaluationdevice 136 or by any other device.

By adjusting or changing the position of the movable reflective element162, the direction of propagation of the illumination light 115 in spacemay be changed, as indicated by direction change 166 in FIG. 5. Thus, byproviding the same advantages as the setup of the detector 118 in FIG.2, the embodiment of FIG. 5 is capable of scanning the illuminationlight 115 through a scan region in space.

The reflective element 160 preferably may be a mirror. Thus, the movablereflective element 162 may be a movable mirror, the position of which,specifically the orientation f which, may be controlled by any arbitraryactuator as known to the skilled person, such as one or more piezoactuators and/or one or more galvoelectric actuators.

The illumination source 114 specifically may be or may comprise at leastone infrared illumination source. Therein, the reflective element 160specifically may be an infrared reflective element, such as a so-called“hot mirror”.

The concept of using one or more reflective elements 160 may beimplemented in other embodiments of the present invention, too. Thus, inFIG. 6, a modification of the detector 118 of FIG. 3 is shown. Again,for most details of the detector 118, reference may be made to thedescription of FIG. 3 above. Still, in the embodiment shown in FIG. 6,as in FIG. 5, a reflective element 160, specifically a movablereflective element 162, is implemented. As can be seen, the reflectiveelement 160 may be combined with the beam-splitting device 146. Thus,the beam-splitting device 146 may be capable of changing its position,specifically its orientation 164, thereby inducing a direction change166 of the illumination light 115 in space, allowing for a scan of afield of view in space.

As outlined above, the beam-splitting device146 may comprise awavelength-selective element, such as a wavelength-selective mirror or awavelength-selective beam-splitter. Thus, the light beam 126 propagatingtowards the imaging device 116 may have a wavelength or spectralcomposition which are not reflected by the reflective element 160,whereas the illumination light 115 is reflected. Again, in thisembodiment, the position of the beam-splitting device 146 may becontrollable, such as by the evaluation device 136 or other devices.

It shall be noted that other embodiments of a movable reflective element162 are feasible, by modifying the setup of FIG. 3. Thus, the reflectiveelement 160 not necessarily has to be combined with the beam-splittingdevice 146. Contrarily, the reflective element 160 may as well beimplemented in different positions in the beam path of the illuminationlight 115. Still, the setup of FIG. 6 allows for a simple and effectiveintegration of the reflective element 160 into the detector 118.

It shall further be noted that the concept of FIGS. 5 and 6 may also beapplied to one or more of a plurality of illumination sources 114 out ofa plurality of illumination sources 114 of the detector 118. Thus, FIG.7 shows a modification of the setup of FIG. 2, in which the at least oneillumination source 114 has an additional illumination source 168 whichis located off-axis, i.e. outside the optical axis 128 and/or outsidethe beam path of the light beam 126. The additional illumination sourcemay even be located outside the housing 144, such as in a separatehousing.

Again, as in the setup of FIG. 5, the illumination light 115 emitted bythe additional illumination source 168 may be deflected by one or morereflective elements 160, more preferably by one or more movablereflective elements 162, such as by one or more movable mirrors.Thereby, by changing the orientation 164 of the movable reflectiveelement 162, a direction change 166 of the illumination light 115 may beinduced, such as for the purpose of a scan.

As outlined above, the detector 118 may further comprise one or moretime-of-flight detectors. This possibility is shown in FIG. 8. Thedetector 118, firstly, comprises at least one component comprising theone or more longitudinal optical sensors 120, such as a sensor stack122. In the embodiment shown in FIG. 8, the at least one unit comprisingthe longitudinal optical sensors 120 is denoted as a camera 119 and mayalso be referred to as the FiP detector. It shall be noted, however,that other embodiments are feasible. For details of potential setups ofthe camera 119, reference may be made to the setups shown above, such asthe embodiment shown in FIGS. 2-6, or other embodiments of the detector118. Basically any setup of the detector 118 as disclosed above may alsobe used in the context of the embodiment shown in FIG. 8.

Further, the detector 118 comprises at least one time-of-flight (ToF)detector 170. As shown in FIG. 8, the ToF detector 170 may be connectedto the evaluation device 136 of the detector 118 or may be provided witha separate evaluation device. As outlined above, the ToF detector 170may be adapted, by emitting and receiving pulses 172, as symbolicallydepicted in FIG. 8, to determine a distance between the detector 118 andthe object 112 or, in other words, a z-coordinate along the optical axis128.

The at least one optional ToF detector 170 may be combined with the atleast one FiP detector having the longitudinal optical sensors 120 suchas the camera 119 in various ways. Thus, as an example and as shown inFIG. 8, the at least one camera 119 may be located in a first partialbeam path 174, and the ToF detector 170 may be located in a secondpartial beam path 176. The partial beam paths 174, 176 may be separatedand/or combined by at least one beam-splitting device or beam-splittingelement 178. As an example, the beam-splitting element 178 may be awavelength-indifferent beam-splitting element 206, such as asemi-transparent mirror. Additionally or alternatively, awavelength-dependency may be provided, thereby allowing for separatingdifferent wavelengths. As an alternative, or in addition to the setupshown in FIG. 8, other setups of the ToF detector 170 may be used. Thus,the camera 119 and the ToF detector 170 may be arranged in line, such asby arranging the ToF detector 170 behind the camera 119. In this case,preferably, no intransparent optical sensor is provided in the camera119, and all longitudinal optical sensors 120 are at least partiallytransparent. Again, as an alternative or in addition, the ToF detector170 may also be arranged independently from the camera 119, anddifferent light paths may be used, without combining the light paths.Various setups are feasible.

As outlined above, the ToF detector 170 and the FiP detector,specifically the camera 119, may be combined in a beneficial way, forvarious purposes, such as for resolving ambiguities, for increasing therange of weather conditions in which the FiP detector may be used, orfor extending a distance range between the object 112 and the detector118. For further details, reference may be made to the descriptionabove.

LIST OF REFERENCE NUMBERS

-   110 shadow-   112 object-   114 illumination source-   115 illumination light-   116 imaging device-   118 detector-   119 camera-   120 longitudinal optical sensor-   122 sensor stack-   124 sensor region-   126 light beam-   128 optical axis-   130 coordinate system-   132 direction of propagation-   134 optical device-   136 evaluation device-   138 data processing device-   140 data memories-   142 connector-   144 housing-   146 beam-splitting device-   148 human-machine interface-   150 user-   152 machine-   154 entertainment device-   156 tracking system-   158 track controller-   160 reflective element-   162 movable reflective element-   164 orientation-   166 direction change-   168 additional illumination source-   170 time-of-flight detector-   172 pulses-   174 first partial beam path-   176 second partial beam path-   178 beam splitting element

1. A detector for determining a position of at least one object, thedetector comprising: at least one longitudinal optical sensor, whereinthe longitudinal optical sensor comprises at least one sensor region,wherein the longitudinal optical sensor is at least partiallytransparent, wherein the longitudinal optical sensor generates at leastone longitudinal sensor signal in a manner dependent on an illuminationof the sensor region by at least one light beam traveling from theobject to the detector, wherein the longitudinal sensor signal, giventhe same total power of the illumination, is dependent on a beamcross-section of the light beam in the sensor region; at least oneillumination source for illuminating the object with illumination lightthrough the longitudinal optical sensor; and at least one evaluationdevice, wherein the evaluation device generates at least one item ofinformation on a longitudinal position of the object by evaluating thelongitudinal sensor signal.
 2. The detector according to claim 1,further comprising: at least one reflective element, wherein thereflective element reflects the illumination light before illuminatingthe object.
 3. The detector according to claim 2, wherein the reflectiveelement is a movable reflective element for being adjusted to at leasttwo different positions, wherein, in the at least two differentpositions, the illumination light is reflected into differentdirections.
 4. The detector according to claim 3, wherein the movablereflective element scans the illumination light through at least onescan region in space.
 5. The detector according to claim 3, wherein themovable reflective element comprises at least one movable mirror.
 6. Thedetector according to claim 2, wherein the reflective element reflectslight in an infrared spectral range, wherein light in a visible spectralrange is transmitted.
 7. The detector according to claim 2, wherein thereflective element is selected from the group consisting of: a mirror; asemitransparent mirror; a mirror or semi-transparent mirror reflectingonly specific spectral regions; a prism; a dichroitic mirror; and a beamsplitter cube.
 8. The detector according to claim 1, further comprising:at least one imaging device, wherein the light beam traveling from theobject to the detector passes through the longitudinal optical sensorbefore impinging on the imaging device.
 9. The detector according toclaim 8, wherein the imaging device comprises a camera chip.
 10. Thedetector according to claim 8, wherein the imaging device comprises aninorganic imaging device.
 11. The detector according to claim 8, whereinthe imaging device comprises a matrix of pixels.
 12. The detectoraccording to claim 8, wherein the imaging device comprises a chipselected from the group consisting of a CMOS chip and a CCD chip. 13.The detector according to claim 8, wherein the imaging device resolvescolors.
 14. The detector according to claim 8, wherein the imagingdevice is a full-color CCD or CMOS chip.
 15. The detector according toclaim 1, further comprising: at least one beam-splitting device, whereinthe beam-splitting device separates the illumination light emitted bythe illumination source before passing the longitudinal optical sensorfrom the light beam traveling from the object to the detector afterpassing the longitudinal optical sensor.
 16. The detector according toclaim 15, wherein the beam-splitting device is selected from the groupconsisting of: a semitransparent mirror; a mirror or semi-transparentmirror reflecting only specific spectral regions; a prism; a dichroiticmirror; and a beam splitter cube.
 17. The detector according to claim15, wherein the beam-splitting device is a movable reflective elementfor being adjusted to at least two different positions, wherein, in theat least two different positions, the illumination light is reflectedinto different directions.
 18. The detector according to claim 1,wherein the longitudinal sensor signal is further dependent on amodulation frequency of the light beam.
 19. The detector according toclaim 1, wherein the illumination source periodically modulates at leastone optical property of the illumination light.
 20. The detectoraccording to claim 19, wherein the at least one optical property isselected from the group consisting of an amplitude and a phase of theillumination light.
 21. The detector according to claim 1, furthercomprising: at least one optical device, wherein the optical devicecomprises at least one element having one or both of a focusing or adefocusing effect onto at least one of the illumination light and thelight beam.
 22. The detector according to claim 21, wherein the at leastone optical device is fully or partially positioned in one or more ofthe following positions in a beam path in between the illuminationsource and the longitudinal optical sensor; in a beam path between thelongitudinal optical sensor and the object; in a beam path in betweenthe longitudinal optical sensor and an imaging device adapted such thatthe light beam traveling from the object to the detector passes throughthe longitudinal optical sensor before passing the optical device andimpinging on the imaging device.
 23. The detector according to claim 22,wherein the optical device comprises at least one element selected fromthe group consisting of: a focusing lens; a defocusing lens; a cameralens; a curved mirror; and a diaphragm.
 24. The detector according toclaim 1, wherein the at least one longitudinal optical sensor comprisesa sensor stack of at least two longitudinal optical sensors.
 25. Thedetector according to claim 24, wherein the sensor stack is composed oflongitudinal optical sensors being arranged such that the sensor regionsof the longitudinal optical sensors are oriented perpendicular to anoptical axis of the detector.
 26. The detector according to claim 1,wherein the illumination light has a wavelength in an infrared spectralrange.
 27. The detector according to claim 1, wherein the illuminationlight at least partially travels parallel to an optical axis of thedetector.
 28. The detector according to claim 22, wherein thelongitudinal optical sensor, the illumination source and, optionally,the imaging device are arranged coaxially with regard to an optical axisof the detector.
 29. The detector according to claim 1, wherein thelongitudinal optical sensor comprises at least one semiconductordetector.
 30. The detector according to claim 29, wherein thesemiconductor detector is an organic semiconductor detector comprisingat least one organic material.
 31. The detector according to claim 29,wherein the semiconductor detector is selected from the group consistingof an organic solar cell, a dye solar cell, a dye-sensitized solar cell,a solid dye solar cell, and a solid dye-sensitized solar cell.
 32. Thedetector according to claim 1, wherein the longitudinal optical sensorcomprises at least one first electrode, at least one n-semiconductingmetal oxide, at least one dye, at least one p-semiconducting organicmaterial, and at least one second electrode.
 33. The detector accordingto claim 32, wherein both the first electrode and the second electrodeare transparent.
 34. The detector according to claim 1, wherein theevaluation device generates the at least one item of information on thelongitudinal position of the object from at least one predefinedrelationship between a geometry of the illumination of the sensor regionby the light beam and a relative positioning of the object with respectto the detector.
 35. The detector according to claim 34, wherein thepredefined relationship takes account of a known power of theillumination.
 36. The detector according to claim 34, wherein thepredefined relationship takes account of a modulation frequency withwhich the illumination light is modulated.
 37. The detector according toclaim 1, wherein the illumination source sends out at least two lightbeams having differing optical properties.
 38. The detector according toclaim 37, wherein the at least two light beams have differing spectralproperties.
 39. The detector according to claim 37, wherein the at leasttwo light beams are modulated with different modulation frequencies. 40.The detector according to claim 1, further comprising: at least onestereo camera.
 41. A human-machine interface for exchanging at least oneitem of information between a user and a machine, the human-machineinterface comprising: the detector according to claim 1, wherein thehuman-machine interface generates at least one item of geometricalinformation of the user with the detector, wherein the human-machineinterface assigns to the geometrical information at least one item ofinformation.
 42. The human-machine interface according to claim 41,wherein the item of information is generated by a body posture and/or amovement of a user.
 43. An entertainment device for carrying out atleast one entertainment function, the entertainment device comprising:the human-machine interface according to claim 41, wherein theentertainment device enables at least one item of information to beinput by a player with the human-machine interface, wherein theentertainment device varies the entertainment function in accordancewith the information.
 44. A tracking system for tracking position of atleast one movable object, the tracking system comprising: the detectoraccording to claim 1, and at least one track controller, wherein thetrack controller tracks a series of positions of the object at specificpoints in time.
 45. The tracking system according to claim 44, whereinthe track controller determines from the series of positions a movementof the object.
 46. A camera for imaging at least one object, the cameracomprising: the detector according to claim
 1. 47. A method fordetermining a position of at least one object, optionally with thedetector according to claim 1, the method comprising: providing at leastone longitudinal optical sensor of the detector, wherein thelongitudinal optical sensor has at least one sensor region, wherein thelongitudinal optical sensor is at least partially transparent, whereinthe longitudinal optical sensor generates at least one longitudinalsensor signal in a manner dependent on an illumination of the sensorregion by at least one light beam traveling from the object to thedetector, wherein the longitudinal sensor signal, given the same totalpower of the illumination, is dependent on a beam cross-section of thelight beam in the sensor region; illuminating the object withillumination light through the longitudinal optical sensor with at leastone illumination source; and generating at least one item of informationon a longitudinal position of the object by evaluating the longitudinalsensor signal with at least one evaluation device.
 48. The methodaccording to claim 47, wherein in the generating, the item ofinformation on the longitudinal position is generated based on an inputsignal of the illumination source.
 49. The method according to claim 47,wherein the input signal of the illumination source is subtracted fromthe longitudinal sensor signal.
 50. A method for producing an item, themethod comprising: producing the item with the detector according toclaim 1, wherein the item is suitable for at least one selected from thegroup consisting of: a position measurement in traffic technology; anentertainment application; a security application; a human-machineinterface application; a tracking application; a photographyapplication; an imaging application or camera application; a mappingapplication for generating maps of at least one space; an application incombination with at least one time-of-flight measurement; an applicationin a local positioning system; an application in a global positioningsystem; an application in a landmark-based positioning system; anapplication in an indoor navigation system; an application in an outdoornavigation system; an application in a household application; a robotapplication; an application in an automatic door opener; an applicationin a light communication system; and an application in conjunction witha stereo camera.